MP 462 hammer, weird results. Maybe some help, maybe I'm missing something?

I have a question about the other guys who have this mould. Sized to .459. I had made up a dummy cartridge to trimmed brass to the crimp groove, and they will not chamber in the 2 45-70s I have here with me. I pulled out the COL gauge, and I'm touching lands at 2.450. what is an average COL on these? Is it normal to have to bury the crimp groove to get the bullet to chamber in a 45-70? I may just use short Hornady brass so I can get a good crimp on my bullets, but I think this is just weird.

Has anyone else experienced this?


**Edited for right COL measurement

What are you trying to use it in? I had a 45-70 contender barrel with that issue, but it had an abnormally short chamber and there were many common bullets it would not chamber.

I have a Marlin 1895, and a Henry Single shot I've tried so far. It may just be these rifles have very short freebore/throats. It's just peculiar because both rifles don't want to chamber.

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Just seat a little deeper and use the Lee FCD. I prefer the situation that you’re in as opposed to the alternative. Bet you’re going to get good combustion throughout the charge range.

I use it in .458socom and not 45-70. But I have to seat it very short too, below minimum COAL for that particular cartridge. The crimp groove is in the neck. It still shoots and feeds fine though. I wish they would have had a .460" option when I got mine though as sizing from .462-.263" (especially with harder alloys) even down to .460" takes a lot of pressure.

Thanks guys, I just wanted to make sure I was not going crazy. I did find out after pulling out the trusty COL gauge and some experimenting that the Hornady cases that are cut short will actually grab the crimp groove and leave me with about .010 jump to the lands. 2.440 COL 2.451/2 average with the COL gauge. I'm going to try it in the short cases and the standard one's and see what shoots best.

At least if they shoot well I'll have a use for these short cases that have been just sitting in a box on the shelf.

It also works out with the NOE 460-396 mould conveniently. https://uploads.tapatalk-cdn.com/201...12fb5c89ae.jpghttps://uploads.tapatalk-cdn.com/201...3fb599f8dd.jpg

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Originally Posted by dkf

I use it in .458socom and not 45-70. But I have to seat it very short too, below minimum COAL for that particular cartridge. The crimp groove is in the neck. It still shoots and feeds fine though. I wish they would have had a .460" option when I got mine though as sizing from .462-.263" (especially with harder alloys) even down to .460" takes a lot of pressure.

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I tried as well in the SOCOM and had a similar experience. I have not gone back to keep trying this yet, but it's on my agenda. I just made a modified case for 458 SOCOM so I can actually work these cast bullet loads and know where it's going to have to be seated to.

How did they do in accuracy? What COL finally worked for you? I need to actually size a couple down to .459 so they will fit in the modified case. I had them at .460 and I can't get it in the neck for the life of me.

I was able to get the Lee 340gn cast in there and it fed well. I am working up a load for that now.https://uploads.tapatalk-cdn.com/201...1850c8d09b.jpghttps://uploads.tapatalk-cdn.com/201...4d2bab1001.jpghttps://uploads.tapatalk-cdn.com/201...c1045f93e1.jpghttps://uploads.tapatalk-cdn.com/201...6036f1e231.jpg

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I believe I am seating them to 1.890" COAL. They are sized to .460" either lubed or epoxy paint (VHT) coated. The thicker the coating the more they hit the throat. My rifle is not really setup for a groups with a 1-4 scope and ALG ACT trigger butI thought the accuracy was pretty good at 50 yards. I got a better ($500) 1-6 scope for my .458 now so I have to test them again, the .458 killed the 1-4. I also plan on getting a lighter trigger, probably a 3.5lb single or two stage trigger. I have a Tromix barrel and the Tromix chamber/case gauge which makes it easy to see if the round will chamber.

Quote:

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Originally Posted by dkf

I believe I am seating them to 1.890" COAL. They are sized to .460" either lubed or epoxy paint (VHT) coated. The thicker the coating the more they hit the throat. My rifle is not really setup for a groups with a 1-4 scope and ALG ACT trigger butI thought the accuracy was pretty good at 50 yards. I got a better ($500) 1-6 scope for my .458 now so I have to test them again, the .458 killed the 1-4. I also plan on getting a lighter trigger, probably a 3.5lb single or two stage trigger. I have a Tromix barrel and the Tromix chamber/case gauge which makes it easy to see if the round will chamber.

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Absolutely, I have a BCA so I figured the Tromix gauge may have been a waste. If they have "pratical accuracy" (2" at 100 yards) I would load them up for sure.

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I don't know if it is a waste but Tromix likely uses a different chamber reamer than BCA so it won't be exactly the same. Tromix uses the used chamber reamers that he takes out of service chambering barrels to make the case gauges. This way the case gauge is just a little bit under the size of the barrel chamber. In a .458socom AR with cast 2" at 100 yards will take some doing.

Side note, there are (at least) 2 different reamers out there for the 458 and they are very close but possibly not identical. Tromix and RRA are the most common ones made on the "real" reamer, licensed from teppo jutsu. The most common other reamer is made by PTG, and can be found in Radical, BCA, and supposedly wilson as well (wilson definitely doesnt have the real one, or didnt last I checked). If there is a difference it is small. I have a radical upper that shoots cast very well which I have been pleased with, and did not learn about the multiple reamers until after visiting the 458 forums after I bought it.

But it does shoot the mihec hammer excellently over h110.

funigui, I have that same mold. Bullets chamber easily in Marlin 1895 Cowboy, but will not in my Shiloh Sharps. I found that if I run loaded rounds into my Hornady sizing die for .44 mag until it just touches the case mouth they will chamber in the Sharps. The diameter of the bullet outside the case is just a little too large for the Sharps, which has no leade.

I just started playing this bullet and I had the same problem with having to seat them in past the crimp groove. I'm putting them through an 1885 Winchester Trapper in 45/70. Once I got the OAL worked out I found after I got the velocity above 1200 FPS they got unstable to the point I couldn't keep them a 4'x6' target board @ 60 yds. Under 1100 FPS I could manage 4" groups out of the little shoulder breaker. I just wondered if any one else had this problem.

I actuallt prefer going past the crimp groove and crimping on a "flat spot" on the boolit. What am I losing by doing this? I always felt it gave me the flexibility to accomplish two things...make up for varying lengths of brass. Lets me seat to the depth thats the best for accuracy in relation to the lands.