6.5x47 pierced primers

[fol8y]

i have fitted a 6.5x47 border barrel to my accuracy international aw about 4months ago, when i first fitted the barrel i loaded a batch of ammo 37.4 g relo 15 and oal 2.730 first few rounds fired ok then it started piercing primers checked oal and i was into the rifling so i backed off to 2.711 4 thou out of rifling no problem rifle shot well until 2 weeks ago 500 rounds later its doing it again same load,same oal same primers checked head space this ok,field head space ai spec ) checked firing pin length after firing this is 1.3mm so is to spec can any one help on this one please as i have some comps in 3 weeks and can t shoot rifle as is as i have to strip bolt every time primers pierce as piece of primer goes into bolt through firing pin hole and jams bolt thanks,mark

 

[billmo]

THE ONE OTHER CONSIDERATION OUTSIDE OF A GUN RELATED ISSUE IS TEMPS. ARE ON THE RISE. IF THERE ARE NO PROBLEMS WITH THE RIFLE, YOU MAY NEED TO BACK DOWN ON YOUR POWDER CHARGE A GRAIN OR SO. SOMETIMES IT ONLY TAKES A PORTION OF A GRAIN TO MAKE A DIFFERENCE IN YOUR LOAD AND YOU MAY FIND IT USEFUL TO CHRONO YOUR LOADS. JUST MY THOUGHTS. BILL

 

[Forum Boss]

Read our article on the 6.5x47 AI Project rifle. Zak Smith experienced a similar problem with his AI.

http://www.6mmbr.com/gunweek084.html

The Accuracy International action has a lot of firing pin protrusion, but most importantly, there is a huge amount of clearance around the firing pin. Excess clearance. This can cause cratering. We saw cratering with loads that were WELL under max in other rifles.

You can switch to CCI primers,harder cup), you can back off your load,a lot), or you can get the firing pin bushed. Greg Tannel can do that inexpensively.

http://www.gretanrifles.com

We do advise to stop shooting the loads that have resulted in piercing. Though pressure may not be the only cause,as explained above), release gas from the pierced primer CAN cause damage to your firing pin or bolt.

One reason you may be seeing effects now, and not before is build-up of carbon and copper in the barrel. When did your barrel last get a good cleaning?

 

[fol8y]

i clean carbon and copper after every shoot i have shot 39 grains of vit 550 123 lapua 2.711 oal today caused cratering in primer but did nt pierce the primer i will try lighter loads on wednesday this load and 37.4 of rel 15 are running at about 2910 through crono ! guys at our club are running 3075 through remi 700s and swing actions, i use cci primers i switched from federal would magnum primers help with a backed of load ?

 

[daj]

I had a similar problem with the 6.5x47L in my TRG-22. Apart from pierced or cratered CCI primers at only moderate pressures, single round feeding was a problem too. Rather than bush the firing pin, I rechambered to .260 Rem and haven't looked back. The problem lies with rifle compatibility and tolerances. The cartridge itself is excellent.

 

[P1ZombieKiller]

You can switch to CCI primers,harder cup), you can back off your load,a lot), or you can get the firing pin bushed. Greg Tannel can do that inexpensively.

http://www.gretanrifles.com

Greg is moving his shop. He will be down till June 1st. I called him Thursday, and he said if I the bolt to him right now, he would do it and get it right back out to me. He runs a top notch 1st class operation.

 

[fol8y]

hi, would love to get greg to sort the bolt but i m in the uk and shipping would take for ever thats if it would get there and back with all the new shipping laws. I know a retired gun smith - engineer who says he could reduce the firing pin as this is 2.1mm and bush the hole i m taking the bolt to him today to have a look . i m going to order a spare firing pin and bolt face from accuracy . don t want to change the caliber as its on the money for accuracy thanks, mark