266 grain cast bullet, the Dolomite special

[dellet]

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.

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.

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



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.
Bipod and squeeze bag off a picnic table (First beautiful sunny day after work this year )

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.

[Dolomite_Supafly]

I would like to thank everyone's help in this. It is really hard to do this as a one man show, especially doing this during what is almost always the bad part of the year for me. And without the help I got this would have probably never happened or at least not any time soon.

Molds will be available at some point, I will not be selling them personally though. My biggest concern in all of this is someone else beating me to the punch and that is why I am waiting on making the molds available. The mold maker has helped me out immensely with both advice as well as making sure no one else gets the dimensional drawings unless I release them.

The production molds have been ordered and these bullets should be available by June, if not sooner. I also have a manufacturer who has shown interest in using this bullet in their line of loaded 300 Blackout ammunition. I should know more about the time we start bullet production.

Last year was "The year of the AK" but for the life of me I cannot seem to remember as much new and exciting things going on as with 300 Blackout this year. I believe this year will turn out to be "The year of the 300 Blackout" with a bunch of new products being introduced. Who would have thought H&K would have guns chambered in our favorite little caliber but they are. Our government has also stood up and taken notice as well. And the reason why is because it IS the most versatile caliber on the planet.

And the best part of this bullet? The unique features that make this bullet shoot so well can be adapted to bullets in other calibers. We are about to release a subsonic 458 SOCOM bullet that uses the same design features. We haven't settled on a weight yet but we are hoping to have a bullet that weighs in excess of 575 grains.

Hey oldphart, PM me your address and I will send you a test mold. That way you can cast plenty to shoot in the meantime.

[Oldphart]

Been trying to figure out how to PM someone. I guess I'm kinda slow here? Any suggestions?

Phil

I finally figured it out, sorry for the inconvience

[ozleux]

Looking forward to these bullets. I think they'll do well in the 300blk and my 308 subsonic. Any idea on availability? Great news for my 458 socom as well !

[Oldphart]

I was fortunate enough for Dolomite_Supafly to send me one of his molds to try and hopefully put some loads on paper. Today I loaded enough to see I they will feed in my AR and do some chrono'ing. But 1st I will post the bullet weights as cast and after sizing and powder coating.

As Cast
1. 265.1 6. 264.9
2. 265.1 7. 264.9
3. 264.9 8. 265.0
4. 265.5 9. 264.9
5. 264.9 1o. 265.5

Sized and Powder Coated
1. 266.3 6. 266.1
2. 266.3 7. 266.2
3. 266.1 8. 266.2
4. 266.3 9. 266.2
5. 265.6 10. 266.0

I just reached into the cans no selecting just grabbing..Now, it did seem like the difference was a little too good! So I did about 100 as cast, and there was a bit more difference but I'd say the most was about .8 of a grain from the lightest to the heaviest.

Here are my chrono results: From a 8.5 in Noveski in an AR platform with a SilencoCo Omega suppressor
Once fired converted FC .223 (military- I say that because the primers were crimped) Winchester small rifle primers, 9.4 grs IMR 4227 (Dolomite_Supafly told me 9.5 grs) and his 265 gr FP bullet sized .3095 powder coated. COAL 2.100

1.1003.6 6. 976.4 lo MAD 7.2
2. 987.2 7. 991.3 ES 31.0
3. 1002.4 hi 8. 986.5 AVG 994.1
4. 1005.1 9. 994.0 SD 9.5
5. 996.7 10. 993.1

I need to put them on paper and post here. Hope to do this in the next week

[Dolomite_Supafly]

I was fortunate enough for Dolomite_Supafly to send me one of his molds to try and hopefully put some loads on paper. Today I loaded enough to see I they will feed in my AR and do some chrono'ing. But 1st I will post the bullet weights as cast and after sizing and powder coating.

As Cast
1. 265.1 6. 264.9
2. 265.1 7. 264.9
3. 264.9 8. 265.0
4. 265.5 9. 264.9
5. 264.9 1o. 265.5

Sized and Powder Coated
1. 266.3 6. 266.1
2. 266.3 7. 266.2
3. 266.1 8. 266.2
4. 266.3 9. 266.2
5. 265.6 10. 266.0

I just reached into the cans no selecting just grabbing..Now, it did seem like the difference was a little too good! So I did about 100 as cast, and there was a bit more difference but I'd say the most was about .8 of a grain from the lightest to the heaviest.

Here are my chrono results: From a 8.5 in Noveski in an AR platform with a SilencoCo Omega suppressor
Once fired converted FC .223 (military- I say that because the primers were crimped) Winchester small rifle primers, 9.4 grs IMR 4227 (Dolomite_Supafly told me 9.5 grs) and his 265 gr FP bullet sized .3095 powder coated. COAL 2.100

1.1003.6 6. 976.4 lo MAD 7.2
2. 987.2 7. 991.3 ES 31.0
3. 1002.4 hi 8. 986.5 AVG 994.1
4. 1005.1 9. 994.0 SD 9.5
5. 996.7 10. 993.1

I need to put them on paper and post here. Hope to do this in the next week

Thank you for posting your results. I have my granddaughter for the week so I have been slacking, I will get the machine cast ones to you as soon as I can.

I do have a question, any problems feeding at the recommended OAL?

I hope you enjoy them.

[Oldphart]

As noted above, I used a COAL of 2.100. I will be going out soon and try 2.110 and 2.120 COAL.

All the rounds shot, so far have feed fine.

I just cleaned the barrel, no leading and very little powder fouling. Just one thing, the first patch through the barrel and out comes a round very thin sliver of lead? Any ideas??

Thanks,

[Dolomite_Supafly]

As noted above, I used a COAL of 2.100. I will be going out soon and try 2.110 and 2.120 COAL.

All the rounds shot, so far have feed fine.

I just cleaned the barrel, no leading and very little powder fouling. Just one thing, the first patch through the barrel and out comes a round very thin sliver of lead? Any ideas??

Thanks,

If it is a round circle of lead, as in a hoop, that is the same size as the case neck I have a pretty good idea of what is going on. It is actually a combination of a several things that come together in some guns to cause this. I have a gun that does it but the best part is it is generally correctable without swapping parts.

The bullets are sized too large for the chamber. In most guns it is not an issue but in some it can cause a problem like you are experiencing. The chamber has a sharp edge where the case mouth meets the throat. The cases are too short, leaving a gap between the case mouth and the step in the chamber for the case mouth.

In some guns the step between the case mouth and the throat has a sharp edge. So when you fire the bullet, especially a bullet slightly too large, it catches on that sharp edge and strips the coating. Something else that can exacerbate the issue is if the gap between the case mouth and the corresponding step in the chamber is too long. This gives the shaved lead a place to go and fills the gap between the case mouth and the chamber with lead leaving behind a ring. And those little lead rings can cause malfunctions that are similar to brass that are not sized properly. You will have to tap on the forward assist to get the gun to completely lock from time to time.

There are a few things that need to happen to correct the problem and they require nothing to be done to the gun. First, make sure the bullets you are using are .309" in diameter. And second, you also need to find out exactly how long your cases need to be to close the gap between the case mouth and the sharp step in the chamber for the case mouth. By closing that gap the bullet has a smoother transition from the case to the bore. I have been told, but cannot confirm, that fire lapping will round that sharp edge.

I normally size my brass at 1.350"-1.355" and in all but one of my guns that is not a problem. But when I fire those rounds through my Contender it sometimes leaves a little lead ring. When I use longer brass the lead ring shows up less often. I have not actually checked how long mine is but I suspect a Whisper reamer was used so there is more of a gap between the case neck an the step in the chamber.

[Dolomite_Supafly]

I was fortunate enough for Dolomite_Supafly to send me one of his molds to try and hopefully put some loads on paper. Today I loaded enough to see I they will feed in my AR and do some chrono'ing. But 1st I will post the bullet weights as cast and after sizing and powder coating.

As Cast
1. 265.1 6. 264.9
2. 265.1 7. 264.9
3. 264.9 8. 265.0
4. 265.5 9. 264.9
5. 264.9 1o. 265.5

Sized and Powder Coated
1. 266.3 6. 266.1
2. 266.3 7. 266.2
3. 266.1 8. 266.2
4. 266.3 9. 266.2
5. 265.6 10. 266.0

I just reached into the cans no selecting just grabbing..Now, it did seem like the difference was a little too good! So I did about 100 as cast, and there was a bit more difference but I'd say the most was about .8 of a grain from the lightest to the heaviest.

Here are my chrono results: From a 8.5 in Noveski in an AR platform with a SilencoCo Omega suppressor
Once fired converted FC .223 (military- I say that because the primers were crimped) Winchester small rifle primers, 9.4 grs IMR 4227 (Dolomite_Supafly told me 9.5 grs) and his 265 gr FP bullet sized .3095 powder coated. COAL 2.100

1.1003.6 6. 976.4 lo MAD 7.2
2. 987.2 7. 991.3 ES 31.0
3. 1002.4 hi 8. 986.5 AVG 994.1
4. 1005.1 9. 994.0 SD 9.5
5. 996.7 10. 993.1

I need to put them on paper and post here. Hope to do this in the next week

And I meant to say it before but that is some amazing consistency for hand cast bullets. That is less than 1% variation, .2% actually, which is amazing and goes a long way to showing how much experience you actually have casting. I can only hope that I am that consistent when I hand cast.

And thanks again for posting your results.

[Oldphart]

As noted above, I used a COAL of 2.100. I will be going out soon and try 2.110 and 2.120 COAL.

All the rounds shot, so far have feed fine.

I just cleaned the barrel, no leading and very little powder fouling. Just one thing, the first patch through the barrel and out comes a round very thin sliver of lead? Any ideas??

Thanks,

If it is a round circle of lead, as in a hoop, that is the same size as the case neck I have a pretty good idea of what is going on. It is actually a combination of a several things that come together in some guns to cause this. I have a gun that does it but the best part is it is generally correctable without swapping parts.

The bullets are sized too large for the chamber. In most guns it is not an issue but in some it can cause a problem like you are experiencing. The chamber has a sharp edge where the case mouth meets the throat. The cases are too short, leaving a gap between the case mouth and the step in the chamber for the case mouth.

In some guns the step between the case mouth and the throat has a sharp edge. So when you fire the bullet, especially a bullet slightly too large, it catches on that sharp edge and strips the coating. Something else that can exacerbate the issue is if the gap between the case mouth and the corresponding step in the chamber is too long. This gives the shaved lead a place to go and fills the gap between the case mouth and the chamber with lead leaving behind a ring. And those little lead rings can cause malfunctions that are similar to brass that are not sized properly. You will have to tap on the forward assist to get the gun to completely lock from time to time.

There are a few things that need to happen to correct the problem and they require nothing to be done to the gun. First, make sure the bullets you are using are .309" in diameter. And second, you also need to find out exactly how long your cases need to be to close the gap between the case mouth and the sharp step in the chamber for the case mouth. By closing that gap the bullet has a smoother transition from the case to the bore. I have been told, but cannot confirm, that fire lapping will round that sharp edge.

I normally size my brass at 1.350"-1.355" and in all but one of my guns that is not a problem. But when I fire those rounds through my Contender it sometimes leaves a little lead ring. When I use longer brass the lead ring shows up less often. I have not actually checked how long mine is but I suspect a Whisper reamer was used so there is more of a gap between the case neck an the step in the chamber.

Thanks for the ideas on the lead sliver, I will try the ideas you suggested.

Now about the consistency of the cast bullets. I believe I was lucky randomly picking the bullets to weight. After noting the consistency I knew it to be a little odd, so I weighted the rest in the batch. The others weighted from 264.5 to 265.8, that still seems to good to be thru; for me anyway.

Sir I do appreciate the help you have given me and I hope I can return your favors.

Again, Thank you,