PDA

View Full Version : 10FP Headspace



kramer
06-25-2014, 09:58 AM
I have an older non-accutrigger 10FP and just grabbed a newer accutrigger model. Both will feed any factory ammo but when I try my reloads I have problems with the newer 10FP. The bolt won't close on many of the rounds I feed it. But those rounds fit fine in the older 10FP as well as every other .308 that I own. I did buy the rifle used and I know the former owner pulled the barrel off when it was new, shot it with another barrel, then put the factory barrel on it when I bought it.

Does this sound like a headspace issue? My reloads fit in my headspace gauges perfectly. I do notice rifle markings on the bullets that won't feed in the suspect rifle. So I loaded a dummy round and kept decreasing the OAL and notice markings when the OAL was below 2.80, like 2.760.

Any thoughts.

earl39
06-25-2014, 12:03 PM
Sounds like a shorter throat is all and not a headspace issue.

josh_m
06-25-2014, 12:40 PM
My 10p has the same issue. I've also been told that it's a short throat. They say to just shoot it a bunch and the throat will work its way out. You can take a sharpie and color the bullet. It will leave marks where the ogive is hitting the lands of the rifeling. Just load shorter till you break it in good. I think I'm loading sierra 168gn to a OAL of 2.776, and it's giving me a .010 jump to the rifeling.

BillPa
06-25-2014, 03:00 PM
I have an older non-accutrigger 10FP and just grabbed a newer accutrigger model. Both will feed any factory ammo but when I try my reloads I have problems with the newer 10FP. The bolt won't close on many of the rounds I feed it. But those rounds fit fine in the older 10FP as well as every other .308 that I own. I did buy the rifle used and I know the former owner pulled the barrel off when it was new, shot it with another barrel, then put the factory barrel on it when I bought it.

Does this sound like a headspace issue? My reloads fit in my headspace gauges perfectly. I do notice rifle markings on the bullets that won't feed in the suspect rifle. So I loaded a dummy round and kept decreasing the OAL and notice markings when the OAL was below 2.80, like 2.760.

Any thoughts.

It can be how the guy set the headspace. If he used short piece of brass (casehead to shoulder) or cranked the barrel down hard on a GO gauge its very possible the chamber is too short for the your resized brass.

Forget the bullet for the moment, try chambering a stick of sized brass, no bullet, powder or primer. If its hard to chamber you'll need to bump shoulders back or reset the the barrel. If it chambers normally then you can fiddle with the bullet seating depth.

Bill

darkker
06-25-2014, 08:38 PM
Doubt he could crush fit a steel go gauge... But crushing down on a brass case/factory round is certainly possible.
Provided, and it's sounds like it does, that a FL sized brass piece chambers, then you just have a short throat.

kramer
06-26-2014, 08:04 AM
It can be how the guy set the headspace. If he used short piece of brass (casehead to shoulder) or cranked the barrel down hard on a GO gauge its very possible the chamber is too short for the your resized brass.

Forget the bullet for the moment, try chambering a stick of sized brass, no bullet, powder or primer. If its hard to chamber you'll need to bump shoulders back or reset the the barrel. If it chambers normally then you can fiddle with the bullet seating depth.

Bill

Ok I've been farting around with it and though my full length sized brass fits in my case gauge it does appear that if I bump the shoulder back a tiny bit (and still gauge fine) they chamber fine. Does this sound like I've got anything to worry about?

BillPa
06-26-2014, 08:51 AM
Ok I've been farting around with it and though my full length sized brass fits in my case gauge it does appear that if I bump the shoulder back a tiny bit (and still gauge fine) they chamber fine. Does this sound like I've got anything to worry about?

Not really, it only means you'll have to either reset the headspace or re-adjust the FL die to bump the shoulder more for that chamber.

There is a easier option, use die shims. http://www.sinclairintl.com/reloading-equipment/reloading-dies/replacement-parts-upgrades/skip-s-die-shim-kit-7-8-14--prod33197.aspx

Set the FL die up using one of the mid range shims (.005"-.006") then use a thicker or thinner shim to adjust the amount of bump you need when sizing brass for the difference in the chamber lengths you loading for.

You might also want (should) invest in a comparator to measure the amount of bump.

Bill