Use of Different Wads and Smokeless Powders

[ronlaughlin]

You will need to clean out the ID between the Primer and Bushing with a drill bit by hand, I actually use a reamer, as it will fill with carbon. As it does, the Primer will see an increase in pressure.

If there is still blow through the primer, after reaming, removing the carbon in the flame channel, you may have a little too much 'crush' on the primers. Too much 'crush' can cause the primer blow through. Too little crush will allow blow by around the primer.

 

[jsteurrys]

I like my Primer crush to be 0.002"-0.003". This is in a Remington 700 ML. Any more than that and you prematurely wear the Bolt Retention Screw. At 0.001", you could have leakage around the Primer. I have no experience with break actions. Your builder should be able to provide you with a target for Primer crush.

 

[Shorty]

Did not know this. Will check it out. Thank you...

 

[GM54-120]

.003 crush is ideal for a break action. You can go slightly more in a Knight or bolt gun.

 

[Shorty]

So i take my calipers and measure the length of a brand new primer. Place it in gun, open it up and remeasure the length of primer to see how much crush i have on it or do i have to fire the gun and then measure?? Ty GM-54...

 

[GM54-120]

Nope DONT FIRE IT

Measure a primer
Insert that primer and snap the action shut (if it needs more than a light snap it may be too tight)
Open the action and remeasure the primer

May want to check several primers for length too. They can vary quite a bit

 

[Shorty]

Will do ...ty..

 

[jsteurrys]

I sort my Primers in 0.001" increments. Federal 209A typically vary 0.004" in length from 0.295" to 0.298". Occasionally I will find a 0.299". Winchester are longer.

 

[frankmillie]

These are manufacturers instructions for adjusting primer crush with adjustable breech plug. It refers to adjusting while trying to close lightly with the unique break trigger Patriot latch. Once adjustment is done it should close using normal pressure.
Note that illustration shows low pressure breech plug. Instructions are same for high pressure breech plug that you have.

 

[Shorty]

Does anyone have pressure traces for vihtavuori n120. Bullet to bore, shooting 250-300 gr. Bullets? Ty

 

[Shorty]

That would be in a .45 cal...ty

 

[GM54-120]

55gr of N120 and a 300gr is 44kpsi or very close. That is around 2350-2400fps too. So i would not exceed that. IIRC that was also the fps i got years ago so i believe the trace to be very very close.

Around 58gr will be max with a 275gr and 60gr max with a 250gr. Bullet brands like the Parker or Fury with thin jackets should give you real close to those numbers. N120 likes a bit more pressure than some powders but its so clean. Probably better to avoid it with the 250gr for temp stability reasons.

 

[frankmillie]

Thank you for the N120 info. I also managed to pick some of that up recently.

 

[GM54-120]

In a rifle that light a 300gr at 2300fps is gunna be a handful but it should be very reliable too. So if needed i see no reason you cant back down a couple grains.

 

[frankmillie]

Does anyone do duplex loads?

 

[jsteurrys]

I use them exclusively. I use the 11/59 N110/H322 with a Barnes 250 gr TEZ and a wool wad. Pressure is around 37-38 ksi IIRC.

 

[jsteurrys]

10/50 IMR SR4759/H4198 is another good one if you have IMR SR4759.

 

[frankmillie]

Sadly I understand that SR4759 is no longer made.

I’m hoping to use 11/59 N110/H322 combination as a cold weather load for 250grain bullets and lighter.

Powders that I have on hand are N110, N120, 5744, H322, IMR4198, Reloader7 and one small container of BH209. I’d be grateful for other useful duplex combinations

 

[michiganmuzzy]

10/50 IMR SR4759/H4198 is another good one if you have IMR SR4759.

Why do you duplex it with H4198? Ive got 8# of sr4759 and as much imr4198 But dont know what situation would call for duplexing them

 

[Shorty]

Cleaned the breechplug today. The crush on the primers was a little to much. Also the carbon build up was a factor in cup pressure. Cleaned the bore real good and breechplug. Only got 2" groups at 100 yds., should have left bore alone. Another lesson learned. The rem. Premier primers measured within .004, the 13 i measured. Easy to clean high pressure breechplug and very easy to set headspace for primer crush. Now i see why some people sort their primers. All said and done another good learning curve. Thank you all for your help...it is very much appreciated...