266 grain cast bullet, the Dolomite special

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dellet
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Re: 266 grain cast bullet, the Dolomite special

Post by dellet » Wed Sep 25, 2019 7:24 pm

armedferret wrote:
Wed Sep 25, 2019 6:58 pm
Dolomite_Supafly wrote:
Fri Sep 13, 2019 1:37 am
armedferret wrote:
Wed Sep 11, 2019 10:16 am
My sweet wooden crate of 100 came in last night. Will see about preppong some brass tonight but I have a weekend getaway coming up I still haven't even begun to pack for...so that takes precedence.

I like that they're noticeably shorter than 208 ELD, as that indicates they may stabilize out of my 6" straight pull pistol.
If you need any help let me know.
Thanks boss. They look and load fantastic.

Sadly with CFE BLK (11.6, 11.8, 12.0) all three powder weights were within 3fps of 950 for an average (5 rounds of each).....and printing 3-4" at 50 yards. This is out of my 10.5" SBR, unsuppressed (until I verified they'd stabilize which they do just fine). Same rig was doing right at MOA with 110 blue tips and shoots about 1.2-1.3 with 208 BTHP/ELD subs, and sub MOA with 125 supers.

I've never had luck with CFE if i'm honest, but was willing to give it a try since it was held in high regard with these, so I guess I'll try 4198 which works really well with my 208 load.
If you are not compressing the CFE yet, keep adding powder. it actually works ok with this bullet. I think I took it to about 14 grains and close to 1500 fps and never had a pressure indication, so don't be afraid to try and move up to 1000 fps.
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armedferret
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Re: 266 grain cast bullet, the Dolomite special

Post by armedferret » Wed Sep 25, 2019 9:40 pm

dellet wrote:
Wed Sep 25, 2019 7:24 pm
armedferret wrote:
Wed Sep 25, 2019 6:58 pm
Dolomite_Supafly wrote:
Fri Sep 13, 2019 1:37 am


If you need any help let me know.
Thanks boss. They look and load fantastic.

Sadly with CFE BLK (11.6, 11.8, 12.0) all three powder weights were within 3fps of 950 for an average (5 rounds of each).....and printing 3-4" at 50 yards. This is out of my 10.5" SBR, unsuppressed (until I verified they'd stabilize which they do just fine). Same rig was doing right at MOA with 110 blue tips and shoots about 1.2-1.3 with 208 BTHP/ELD subs, and sub MOA with 125 supers.

I've never had luck with CFE if i'm honest, but was willing to give it a try since it was held in high regard with these, so I guess I'll try 4198 which works really well with my 208 load.
If you are not compressing the CFE yet, keep adding powder. it actually works ok with this bullet. I think I took it to about 14 grains and close to 1500 fps and never had a pressure indication, so don't be afraid to try and move up to 1000 fps.
I think i'm just more confused as to why such a decent window of charge weights yielded no change in velocity.

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Re: 266 grain cast bullet, the Dolomite special

Post by dellet » Wed Sep 25, 2019 10:54 pm

armedferret wrote:
Wed Sep 25, 2019 9:40 pm
dellet wrote:
Wed Sep 25, 2019 7:24 pm
armedferret wrote:
Wed Sep 25, 2019 6:58 pm


Thanks boss. They look and load fantastic.

Sadly with CFE BLK (11.6, 11.8, 12.0) all three powder weights were within 3fps of 950 for an average (5 rounds of each).....and printing 3-4" at 50 yards. This is out of my 10.5" SBR, unsuppressed (until I verified they'd stabilize which they do just fine). Same rig was doing right at MOA with 110 blue tips and shoots about 1.2-1.3 with 208 BTHP/ELD subs, and sub MOA with 125 supers.

I've never had luck with CFE if i'm honest, but was willing to give it a try since it was held in high regard with these, so I guess I'll try 4198 which works really well with my 208 load.
If you are not compressing the CFE yet, keep adding powder. it actually works ok with this bullet. I think I took it to about 14 grains and close to 1500 fps and never had a pressure indication, so don't be afraid to try and move up to 1000 fps.
I think i'm just more confused as to why such a decent window of charge weights yielded no change in velocity.
I am not a fan of CFE, but this bullet is one of the few it can work with.

If your average was 950 +/- 5 I would believe it but, would not be surprised if your ES 100 fps with the light load and dropped to 80 fps with the heaviest. Just got lucky that the average of three bad loads were close. That’s just the way CFE works. Then once you get some compression, the ES drops and it starts being predictable.

If your COL was anything longer than 2.100” you were not on the powder.

It might be worth a try to load some with 12.2-12.6 at 2.100” and see what happens.
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Re: 266 grain cast bullet, the Dolomite special

Post by armedferret » Thu Sep 26, 2019 7:19 am

dellet wrote:
Wed Sep 25, 2019 10:54 pm
armedferret wrote:
Wed Sep 25, 2019 9:40 pm
dellet wrote:
Wed Sep 25, 2019 7:24 pm


If you are not compressing the CFE yet, keep adding powder. it actually works ok with this bullet. I think I took it to about 14 grains and close to 1500 fps and never had a pressure indication, so don't be afraid to try and move up to 1000 fps.
I think i'm just more confused as to why such a decent window of charge weights yielded no change in velocity.
I am not a fan of CFE, but this bullet is one of the few it can work with.

If your average was 950 +/- 5 I would believe it but, would not be surprised if your ES 100 fps with the light load and dropped to 80 fps with the heaviest. Just got lucky that the average of three bad loads were close. That’s just the way CFE works. Then once you get some compression, the ES drops and it starts being predictable.

If your COL was anything longer than 2.100” you were not on the powder.

It might be worth a try to load some with 12.2-12.6 at 2.100” and see what happens.
Yeah i think i was at 2.120". Will try your suggestion (although admittedly it may be a while, nearest range is over an hour and all the ones within 3 hours are public so i tend to avoid weekends) and pop back in here when I have more results.

Thank you!!

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Re: 266 grain cast bullet, the Dolomite special

Post by armedferret » Wed Oct 02, 2019 6:14 pm

dellet wrote:
Wed Sep 25, 2019 10:54 pm

It might be worth a try to load some with 12.2-12.6 at 2.100” and see what happens.
Good sir I have news. But it isn't delightful heh.

12.2 averaged just a hair under 1k for 10 rounds but SD/ES were still pretty vomitous (sd over 40). 12.4 was supersonic for all but one shot, but sd came way down to about 20. Sadly this was the paper. At 50 yards.

12.2:

Image

12.4:

Image

Needless to say I've had my fill of CFE BLK. :P didn't even bother to shoot the 12.6 loads. Save the projectiles for other powder. May try imr4198 unless theres good reason not to as it works magnificently with 208s out of this same SBR.

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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly » Wed Oct 02, 2019 11:10 pm

Are you belling the case mouth before seating? These, like all cast bullets, need a bell on the case mouth. If not the coating, and diameter, can be removed causing stability issues.

If you have IMR 4227 I would try 10 grains then go up or down from there. I would start with the overall length you are using to ensure it feeds.

Are you getting any little lead rings in the chamber?

And finally, what kind of dies are you using? If you use RCBS give them a call and tell them you need an expander ball for 7.62x39. They will send you one for free. If not you might consider buying a set. Sometimes the case neck can reduce the size of the bullet and a larger neck helps.
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Re: 266 grain cast bullet, the Dolomite special

Post by dellet » Thu Oct 03, 2019 12:24 am

Dolomite_Supafly wrote:
Wed Oct 02, 2019 11:10 pm
Are you belling the case mouth before seating? These, like all cast bullets, need a bell on the case mouth. If not the coating, and diameter, can be removed causing stability issues.

If you have IMR 4227 I would try 10 grains then go up or down from there. I would start with the overall length you are using to ensure it feeds.

Are you getting any little lead rings in the chamber?

And finally, what kind of dies are you using? If you use RCBS give them a call and tell them you need an expander ball for 7.62x39. They will send you one for free. If not you might consider buying a set. Sometimes the case neck can reduce the size of the bullet and a larger neck helps.
Here is what Dolomite is talking about, this was back on page 3. This was really the first powder coated bullet I worked with that was not ready for sale, so there was a huge learning curve of what might make differences either in loading techniques or production changes for this bullet.

The base is the steering end, and it shows below the importance of not damaging the base or coating when seating. When I talked to Dolomite about it, I understood immediately what he was talking about, but would not have believed the difference without seeing it.
dellet wrote:
Tue May 09, 2017 11:31 pm
dellet wrote:First go with the final version was an exercise in making as many mistakes loading as possible while loading and back up why you should not do them on paper.

Dots are 1" for reference.
Image
Shot a 50 yards

Group on the right is what happens when you grab a bunch of random brass. I could feel the difference in neck tension while seating the bullets. Top shot is cold clean bore. These were loaded at 2.110, the shortest I have ever seated them and the worst group I have ever had.

Group on the left seated at 2.145", this length is max length for my chamber in a Model 7. I also changed to matching headstamps. The hole on the bottom right shaved a little when seating while seating. I actually shaved two rounds before getting things adjusted correctly. After the flyer instead of shooting the second one I pulled the bullet. It's below.
Image
Shaving the coating is a bit of a problem, but cutting the edge of the base a sure way to have a flyer.

Been fighting weather for a good shooting session, but again a lot of promise for very little work. Hope to hear from some others.
Just can't seem to go 5/5

Image

Bottom group same load as top left, difference is brass was belled and crimped to remove. 5 at 50 yards. Group measures outside to outside .930" with flyer .650" without. That should be MOA potential at 100, I will try it after I tighten up the ES a little.

2.145" COL
LC converted brass 1.360"
9.8 gr N120
Remington 7 1/2 primer
Velocity 1030 avg.

Remington Model 7 1/7 twist.
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I'm pretty surprised so far. I think I'm about 50 rounds fired in three different rifles. If I can get the other two dialing in this quickly, I will be very happy. May try the 1/10 twist next. If there has been an improvement in casting/coating quality, that is where it will show up and at distance.
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Re: 266 grain cast bullet, the Dolomite special

Post by armedferret » Thu Oct 03, 2019 5:41 am

Sounds like I may be done with these then. It already takes nearly 2 hours for 50 rounds, and thats without adding another handful of steps. I don't have that kind of time.

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Re: 266 grain cast bullet, the Dolomite special

Post by dellet » Thu Oct 03, 2019 8:57 am

armedferret wrote:
Thu Oct 03, 2019 5:41 am
Sounds like I may be done with these then. It already takes nearly 2 hours for 50 rounds, and thats without adding another handful of steps. I don't have that kind of time.
I would suggest you give up all cast and coated bullets then, or get used to shooting patterns rather than groups. Most people are pretty happy to add a single step and shrink their groups from 3-4 MOA to 1.

The only step you are adding is belling the case. Almost all seating dies can be set to remove the bell and if you are dropping powder on a press instead of by hand you can bell it case then.

It would also probably help with the stability issue you are having.
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Re: 266 grain cast bullet, the Dolomite special

Post by Dolomite_Supafly » Thu Oct 03, 2019 1:09 pm

armedferret wrote:
Thu Oct 03, 2019 5:41 am
Sounds like I may be done with these then. It already takes nearly 2 hours for 50 rounds, and thats without adding another handful of steps. I don't have that kind of time.
The only additional step should be belling the case mouth. Everything else is just a matter of adjusting the die to remove the bell.

Cast always tend to be a little more finicky compared to jacketed bullets. But cast bullets can definitely be as accurate as most jacketed bullets they just take a bit more care.

If you are done please contact ACME to set up a refund. They are a great company that supports the shooting sports. They appreciate every customer.

Sorry these did not work out for you.
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