Rifle Primers vs Pistol Primers & Other Solutions

[kombi1976]

I'm loading for a 25-20 and with jacketted bullets have had a lot of success.
Cast bullets are providing a reall obstacle however.
The main problem is that the loads recommended by ADI are not powerful enough to seal the case neck.
The only powder recommended for the job is AR2205 with a minimum load of 6gn & a maximum of 7gn, for both 71gn and 85gn cast bullets.
AR2205 is on the same level as H110 to give you an idea.
Presently I'm using a 6.5gn load behind some 75gn FPRN cast projectiles and they continue to blacken down the outside of the case neck and leave a huge amount unburnt powder.
It's unsafe and isn't exploiting the powder load.
Would changing to pistol primers solve the problem?
Are small pistol primers the same size?
Would increasing the charge to 8gn work?
It's still 1.3gn below the minimum charge for 75gn jacketed bullets but I think the extra powder might solve the problem.

 

[blindside]

I normally like to step in on these,but unfortunately my usual suggestion as to how to fix lead,is to wrap a copper jacket around it...I hates cast stuff

 

[Rapt]

Small pistol primers are the same size as small rifle primers, but there's no way I'd use them on a rifle cartridge.

The reason is that pistol primers have a thinner softer cup so they puncture more easily than rifle primers. The rifle primers take more pressure safely. Many shooters shooting very hot pistol loads in things like 9x23 or 38 super use rifle primers in their pistols for this reason.

Also they say riffle primers burn longer and hotter than pistol primers. So I wouldn't think going down in primer will help.

So I'd say its a no on the pistol primers in your rifle.

Other options...

Well if your cases have been used or resized a lot or very heavily I would consider annealling the case necks as they may not be sealing because they've work hardened too much. Especially since its a relatively "low" pressure load.

Also since you're leaving lots of unburnt powder it sounds to me like the bullets are too loose in the case neck. This could be due to neck tension/"crimp" or it could be because the cast bullets are too soft an alloy to hold well.

Or the powder you're using is either old and bad and or just not well suited. I'd seriously consider trying different powders as suggested by different reloading manuals. There is a ton of other loads listed out there on the web from reputable sources like Hodgdon, Winchester, Speer....

Finally make sure you use a chrony to ensure that your loads are "safe" by checking the velocity of the bullet. As long as you're below the maximum speed listed for the powder then your load is safe pressure wise.

 

[joe-nwt]

As long as you're below the maximum speed listed for the powder then your load is safe pressure wise.

Rapt has a lot of good advice, except maybe this tidbit. You should chrono your loads but book max is not necessarily 100% safe in 100% of the firearms 100% of the time. Start low, and work up while chronoing.

 

[guntech]

Maybe you need a magnum pistol primer....

You could also anneal the neck of a couple of cases and see if that helps the situation.....

 

[chappy]

i will go with guntech. try the magnum pistol primers for low pressure lever guns. the pistol primers are softer and the lever guns don't seem to hit the primers as hard. i use win pistol primers in a marlin with excelent results. acuracy is far better than rifle primers.

 

[Mystic Precision]

I think your big problem is using a very slow powder. The 25-20 case holds approx 20gr of blackpowder which is very coarse. That equates to a smokeless powder capacity much higher. That case, if memory serves me correctly is in the 45LC case volume range. Using very small volumes of a H110 type powder will not generate the pressure curve you need. If fact, can lead to some very dangerous secondary detonation problems.

NO idea about your powder types. But from your comment, that is my suggestion.

For these type of reduced cast loads, very fast pistol and SG powders are used. Powders like Titegroup, Red dot, 700X, HP38/Win231 work very well for this type of shooting. The new Hodgdon Trail Boss is meeting with rave reviews. No idea what the equivalent in Australia is but many are imported from your manf.

You should look at cowboy loads on the Hodgdon or IMR site, Lyman or Lee load manuals. This will give you lots of info. Pressures are still low but much sharper which can help with bullet obturation and opening that case mouth.

Anneal the necks soft, neck size only enough to hold the bullet are just a couple of easy ways to make reduced loads less troublesome.

As to going with a magnum primer? That is something you can adjust once you are using the proper powder. In general, not needed but each rifle is different. An easy alternative is the Win LP primer, kind of in between a pistol and rifle primer and will handle 'hotter' ignitions.

 

[CanAm]

FYI - ADI makes most of Hogdons extruded powders. ADI offers burn rate chart to compare. I would use the Hogdon site to look up loads then compare them to the ADI equivilent. Also, the technical department at ADI is very helpful in answering questions and it might be worth calling them.

 

[oldbadger]

Andy, what % fill are you getting? If it is deep down in the case, you may need to compress it a bit.You may want to consider an over powder fill such as dacron. I use this in reduced loads to keep the powder near to the primer.