266 grain cast bullet, the Dolomite special

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2manyToys
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Re: 266 grain cast bullet, the Dolomite special

Post by 2manyToys »

Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
You're close. Remember thar this bullet is a bore rider. It will likely be in contact with the throat/bore when you chamber it

I load them at 2.120 COAL with 7.2 grains of N105. This resulted in an average of 975 FPS, 24 ES and 7 SD. This was with LC converted brass and CCI #41 primers.

This was out of an 8.5" barrel, suppressed, gas port opened up with an AGB. I'm pretty close to sea level.

This load grouped really well at 25 yds, but opened way up at 100. I'll likely speed them up a little next time.
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Dolomite_Supafly
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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly »

Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
Are you riding the bolt or using the bolt release?

It sounds like you might have a tighter than SAAMI chamber. At 2.05" they should just fall into the chamber with no resistance. They are designed to slightly engrave the bullet upon chambering but not stop it from chambering at ~ 2.10"-2.12".

Are you getting a lot of resistance When seating? As in enough to deform the nose.

When did you buy these? How many?
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dellet
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Re: 266 grain cast bullet, the Dolomite special

Post by dellet »

Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
I wouldn’t try 8 of N105 at that length. Hate to see a new rifle need work after a shot or two.

Get the chamber issue worked out before you start loading. If it is a tight chamber, there is not a published load out there that will be safe to shoot.
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Re: 266 grain cast bullet, the Dolomite special

Post by Smurky »

Dolomite_Supafly wrote:
Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
Are you riding the bolt or using the bolt release? No I don’t think that’s the issue in fact when one did chamber at 2.100 the case extracted after a LOT of force pulling the charging handle, (thought I’d rip the rim off the case) but the bullet stuck in the chamber. Took a wood dowel to get the bullet out with a light tap. As noted above closing the bolt on the longer dummy rounds with a light/medium crimp moves the bullet into the case.

It sounds like you might have a tighter than SAAMI chamber. At 2.05" they should just fall into the chamber with no resistance. They are designed to slightly engrave the bullet upon chambering but not stop it from chambering at ~ 2.10"-2.12".

Are you getting a lot of resistance When seating? As in enough to deform the nose. i would say no, as stated I use the NOE expander and they seat easily and there are no visible marks or mushrooming on the nose.

When did you buy these? How many?[ Nov or Dec 2017, 500 from Acme/quote]

Thanks for the response DS, really appreciate it. I have loaded 110 Vmax, 150 Hornady FMJ, 208 Hornady BTHP, 220 Sierra MKs and Palmetto 203’s without issue.

Thanks again for the response.
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Re: 266 grain cast bullet, the Dolomite special

Post by Smurky »

dellet wrote:
Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
I wouldn’t try 8 of N105 at that length. Hate to see a new rifle need work after a shot or two.

Get the chamber issue worked out before you start loading. If it is a tight chamber, there is not a published load out there that will be safe to shoot.
It’s not a new rifle, had it for 2 years and have shot a couple hundred rounds of factory ammo through it initially and more than 1k of my loads. I’ve loaded 110 Vmax, 150 Hornady FMJs, 208 hornady BTHP, 220 Sierra MKs and 203 Palmetto. I haven’t witnessed any pressure signs on any of those loads. I’ve used H110, A1680, CFE Blackout, IMR4227 for those loads. Because I shoot it often I’ve been looking for a reasonably accurate bullet at a good price. I use the rifle in a carbine league in the summer, it’s similar to USPSA but with carbines.

I load pistol for USPSA, mostly 40S&W, rifles I reload .223 Remington, 6.5 Creedmoor and .308. I reloaded some in the 80’s, mostly for revolvers and 45 ACP. Because of family responsibilities and work didn’t shoot or reload much for 30 years. For only about the last 5 years that I’ve been reloading and shooting more. Trying to figure out how much I don’t know of which I know there is a lot.

That said Dellet thanks for your contributions to this forum, I find them very valuable. I was thinking the same thing about that load. Does Quickload give this sort of prediction?
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dellet
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Re: 266 grain cast bullet, the Dolomite special

Post by dellet »

Smurky wrote:
dellet wrote:
Smurky wrote:Now that it’s finally getting warmer I’m trying to find a load that will work with these bullets. I Sized them on a Redding full size die, used a NOE .312 x 308 expander in a Lee Universal and crimped with a Lee FCD. I didn’t change the crimp from working my previous loads. Worked up some dummy rounds and they’ll cycle out of the mag but unless I shorten them to about 2.050 OAL the bolt won’t close. At 2.050 without powder the cartridge was at 2.0270 with a few marks on the nose of the bullet.

I don’t think I can get these to work any longer in my rifle. The rifle is Mod 1 mk109 upper. 9.5 inch piston Operated upper that I run with a Silencer Co Saker suppressor.

I also checked powder capacity and 8 grains of N105 would be compressed with this OAL.

Looking for opinions, is this just a no go because the cartridge has to be so short? I have N105, N120 IMR 4227 and H110, SW blackout and have a little CFE blackout left. My thoughts here are that a faster powder may be the way so I was thinking N105 or H110 and would appreciate any opinions.
I wouldn’t try 8 of N105 at that length. Hate to see a new rifle need work after a shot or two.

Get the chamber issue worked out before you start loading. If it is a tight chamber, there is not a published load out there that will be safe to shoot.
It’s not a new rifle, had it for 2 years and have shot a couple hundred rounds of factory ammo through it initially and more than 1k of my loads. I’ve loaded 110 Vmax, 150 Hornady FMJs, 208 hornady BTHP, 220 Sierra MKs and 203 Palmetto. I haven’t witnessed any pressure signs on any of those loads. I’ve used H110, A1680, CFE Blackout, IMR4227 for those loads. Because I shoot it often I’ve been looking for a reasonably accurate bullet at a good price. I use the rifle in a carbine league in the summer, it’s similar to USPSA but with carbines.

I load pistol for USPSA, mostly 40S&W, rifles I reload .223 Remington, 6.5 Creedmoor and .308. I reloaded some in the 80’s, mostly for revolvers and 45 ACP. Because of family responsibilities and work didn’t shoot or reload much for 30 years. For only about the last 5 years that I’ve been reloading and shooting more. Trying to figure out how much I don’t know of which I know there is a lot.

That said Dellet thanks for your contributions to this forum, I find them very valuable. I was thinking the same thing about that load. Does Quickload give this sort of prediction?
Yes it does, but for bullet like that you need to create it's own profile and I have not done that. I ran a 240 SMK with 8 grains and 100% case fill. Predicted pressure was something like 79k. Changed the seated depth .010" shorter, jumped to 85k. Moved it out .060" dropped to about 59k. It's a very worthwhile addition to any loading bench.

It is a great powder, I actually use it in a 25 Rimfire that's about 125 years old. It's sensitive, but very predictable.

Do you still have any of the bullets that jammed?

It would be very helpful if you could measure one and compare to another that had not been chambered. That would be great info for Dolomite to have.
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Re: 266 grain cast bullet, the Dolomite special

Post by Smurky »

This is nagging at me, I used the Hornady gauge to determine where the lands are in my rifle with the bullets I have on hand. 110 VMax, 150 FMJ, 208 BTHP and the 203 Palmetto. I also did the DS and that is 2.055 as I’ve mentioned. I measured my upper than compared to the Sheridan gauge. The measurement between the upper and the Sheridan gauge are with .005 for all the bullets except the DS. The 110 is almost out of the neck and the cannelure on the 150 is about way outside the neck so unusable at those lengths. I know the DS is suppose to ride in the bore so the Sheridan is not a good comparison. As mentioned in my rifle the DS is in the lands at 2.0550 and to fit in the Sheridan I measure it at 1.9350.

So is the bullet expected to be into the bore .12, is that the design?

Is the chamber in my rifle suspect and/or should I do some additional analysis seems to closely mirror the Sheridan gauge?

Appreciate corrections, comments and suggestions,

Thanks
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Re: 266 grain cast bullet, the Dolomite special

Post by Smurky »

dellet wrote:
Do you still have any of the bullets that jammed?

It would be very helpful if you could measure one and compare to another that had not been chambered. That would be great info for Dolomite to have.
I do, may be my shaky hands but they run from .3015 to .3025 near the nose, the new ones measure about the same. One of them I seated and ejected at 2.0750 and that one mushroomed a bit and measure .304-.305.

I did use an Geissele alignment rod to check the alignment of the brake and suppressor. I measure it at .2980 and it slides easily down the bore if that means anything.

Thanks again for the response and input.
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dellet
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Re: 266 grain cast bullet, the Dolomite special

Post by dellet »

Smurky wrote:
dellet wrote:
Do you still have any of the bullets that jammed?

It would be very helpful if you could measure one and compare to another that had not been chambered. That would be great info for Dolomite to have.
I do, may be my shaky hands but they run from .3015 to .3025 near the nose, the new ones measure about the same. One of them I seated and ejected at 2.0750 and that one mushroomed a bit and measure .304-.305.

I did use an Geissele alignment rod to check the alignment of the brake and suppressor. I measure it at .2980 and it slides easily down the bore if that means anything.

Thanks again for the response and input.
Did you have to pound the bullets out from the muzzle that are .304+? They should not mushroom going into the chamber.

The other option would be they deformed when seating, possibly a compressed load?

There's a coulpe things I would try.

One is to load a round with no powder and let it push back into the case when loaded. Measure before and after. It will probably be shorter, but if it's longer it definitely stuck and pulled out on extraction.

Polish the nose of a couple bullets until they can be pressed with light finger pressure all the way to the step on the bullet in the muzzle end of your Sheridan. Then try them in your rifle.

Check concentricity of the loaded rounds. With such a long nose that rides the bore, they have to be absolutely straight.

I would have expected the bullets that stuck in the rifling to have visible flat spots where the lands were. And to have had measurements less than they went in.

If the bore is tight on your barrel I would expect you to have a diameter of .2995 or so. But if it's a 5R they are very hard to measure.

Those are some things I'd check.
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Freedom1973
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Re: 266 grain cast bullet, the Dolomite special

Post by Freedom1973 »

Dolomite, Dellet, and other page veterans,
Where should I start with the 245gr version of the Dolomite Special? I have N105,N110,N120 and IMR4227. Using 8.5" 1/6 x-caliber barrel AR, FABCG,Silent capture spring, AGB, Lancer mags. I have data on the 265gr and just want a starting AOL. Thanks in advance.
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