[nemohunter]

OK i did it just to see if it could be done. FIRST thing i did was research. pressure of all small pistol primered brass was researched and i came out with around 41,000 CUP forthe top end. OK start digging for a load that is under that. nothing in the regular manuals. then i look at the Lee manual. IMR has some 4350 loads that are under that with 62 gr bullets. load up a few of those. the cases are almost full to the mouth. then i put some Tac starting loads toghether. i'm sure they are higher in pressure as well. got my gun all clamped down. got my string and pulled the trigger on the 4350 loads. they shot AND cycled the rifle just fine. accuracy was OK but not great. primers looked like brand new save the firing pin indentation. i'm sure you could push this load faster IF you could get more powder in the case. i could probly go .2 or .3 more with the Rem brass i'm running. next up was the starting load of Tac. as before first one clamped down with the string. pow. everything worked normal so i settle in behind it. shot a 1.5" group at 100 yds. again primers looked unused for all purposes save the FP hit. i know i can push these harder if i feel i need to. maybe just a bit more to see if they would tighten up a bit. i know the gun shoots sub MOA with those bullets.

these are MY experiances with my componets in my rifle. the results may not be the same for you. if you dont feel safe doing this then dont. i did it just to see IF it could be done and have a reliable weapon.

Rem brass
62gr Armscore FMJBT
Magtech SPM primer
IMR 4350 and RS Tac powder.

Custom built .223 rifler for testing.

Cav arms lower with M1S LPK.
Cardinal forge upper with Dez arms 16" pencil barrel.
J&T railed gas block.
RRA BCG and CH.

 

[LKirchoff68]

I hope this works. I can get 1000's of SP Mag primers right now.

 

[nemohunter]

I hope this works. I can get 1000's of SP Mag primers right now.

it works. i did it just to see if the rifle would function and it would shoot with reasonable accuracy. it does.

that said i would not do it unless i had too. i still have SRP on hand for now but i'll be out in a bit. if the ones i have on order dont come in then it will be this just to keep me shooting.

 

[type911]

I think different manufacturers may have different results. My co-worker ran the same test but loaded 10 rounds in the magazine. He fired one round but the whole magazine went. Every time the bolt chambered a round the firing pin struck the primer hard enough to send the next round. It is more of a problem with the hardness or lack there of, of pistol primers. In a bolt gun I think it would be OK.

 

[ron169]

I think different manufacturers may have different results. My co-worker ran the same test but loaded 10 rounds in the magazine. He fired one round but the whole magazine went. Every time the bolt chambered a round the firing pin struck the primer hard enough to send the next round. It is more of a problem with the hardness or lack there of, of pistol primers. In a bolt gun I think it would be OK.

If you were expecting that, I would think that would be fun.... But hey, thats just me. So other than the uncontrolled auto fire, why not use Small pistol primers in rifle cases? I think from what I read above there is a problem with too much pressure.

 

[Equalizer_2]

... why not use Small pistol primers in rifle cases? I think from what I read above there is a problem with too much pressure.

This is my understanding also, the primer cups are too soft in many cases. But this depends on who makes the primers. I have heard that Winchester has some of the hardest primer cups.

 

[nemohunter]

i used magtechs for these rounds. i would not try it with fedrals or Remingtons.

 

[angsniper]

I used small pistol primers in my 5.56 once by mistake. I didn't realize it until after the fact. Could not tell the difference in accuracy at all but I didn't chrony the rounds.