I've looked for clues all over the internet and in my reloading books, but so far I have come up short in trying to solve a problem I'm having with my 308 loads. I've been working on solving this off and on for a few months with no luck.
I have loaded successfully for years in a bunch of handgun calibers and so far, all my .223 loads have been solid, no problems there. However, I am relatively new to loading 308. This could be just another one of my idiot moments, and if so, I could use some help from you guys to see what I'm messing up here.
The problem I'm having is that after I pull the trigger on my 700, sending a bullet downrange, I try to extract the case, but I have an incredibly difficult time opening the bolt and pulling it rearward. The brass gets stuck in the chamber. Because this happened on my first reloads, I was afraid that I accidentally over-charged my cartridges somehow. After further analysis, I don't think this is the problem, though, because it happens on all my cartridges and for every single one, I trickle my powder into the cases and measure carefully on my Dillon digital scale. I chronographed everything, as I always do when working up a new load. Here are my load data:
--Remington 700 SPS tactical mounted in an XLR Industries chassis.
--178 grain A-max
--Varget powder, charge weights varying between 43.0 and 44.5 grains in 0.3 grain increments
--Velocities ranged between approximately 2500 and 2570fps. I had been hoping for a little higher velocity, but I guess I'm glad I wasn't accidentally shooting super hot rounds.
--Winchester large rifle primers
--Once-fired Prvi Partizan Win 308 brass that had been shot by me in either the Rem 700 or my DSA SA58
--Brass was deprimed, full-length resized, and then trimmed to 2.015 with a Giraud.
--Cartridge OAL was roughly 2.820.
--Dillon 550B was used with Dillon rifle dies for resizing, bullet seating, and (light) crimping.
--Most primers showed some pressure signs, slightly flattened primers, but not much worse than some factory loads.
--All rounds were checked with a Dillon case gauge and found to easily slide in/out. Both ends of the cases fit inside the min/max steps on the case gauge.
--An RCBS precision mic was used to set headspacing on the resizing die. Headspacing length was measured on factory rounds before and after firing in the 700. I set the resizing die to ensure that cases were bumped back by 0.002-0.003 after being fired in the 700 (20+ rounds of factory Prvi Partizan 168 grain match)
Factory rounds cycled without problem through the gun, so I doubt there's anything wrong with the 700. Dummy reloads chambered fine. The bolt closed without much difficulty on the reloads, but got stuck after firing. Empty brass cases from fired reloads will not chamber without excessive force, as expected after having ripped them out of the chamber. I colored all over some fired cases with Sharpie marker and attempted to chamber them again in order to highlight wear marks on the brass. It looks like the only wear marks are light, appearing around the neck and then just behind the shoulder.
I've measured every critical dimension I can think of on the factory loads, factory load empty brass, reloads, and reload empty brass. Every dimension on the reloads is matched or undersized by a small margin. I have tried some reloads with head spacing set 0.002 below that of fired empty factory cases and other reloads set 0.005 below fired empty factory cases. I have also varied crimping between medium and almost non-existent. Modulating these two factors had no meaningful impact on anything I could detect.
The only interesting difference I have found between factory loads and my reloads is the brass case length after firing. Brass from factory loads doesn't seem to grow in length more than 0.003 during firing. However, my reload brass grows up to about 0.010 during firing. In other words, my brass is flowing a lot more on my reloads than it does on factory loads. Is there any way that this indicates why my fired brass gets stuck in the chamber?
Given my load data and velocities, is it possible that my loads are too hot? 43.0 grains of Varget should not be too high for this bullet, at least according to all the information I've collected from publications and also from other shooters. Lower charges do not seem to suffer less from the problem I'm experiencing here. What's going on????
I have loaded successfully for years in a bunch of handgun calibers and so far, all my .223 loads have been solid, no problems there. However, I am relatively new to loading 308. This could be just another one of my idiot moments, and if so, I could use some help from you guys to see what I'm messing up here.
The problem I'm having is that after I pull the trigger on my 700, sending a bullet downrange, I try to extract the case, but I have an incredibly difficult time opening the bolt and pulling it rearward. The brass gets stuck in the chamber. Because this happened on my first reloads, I was afraid that I accidentally over-charged my cartridges somehow. After further analysis, I don't think this is the problem, though, because it happens on all my cartridges and for every single one, I trickle my powder into the cases and measure carefully on my Dillon digital scale. I chronographed everything, as I always do when working up a new load. Here are my load data:
--Remington 700 SPS tactical mounted in an XLR Industries chassis.
--178 grain A-max
--Varget powder, charge weights varying between 43.0 and 44.5 grains in 0.3 grain increments
--Velocities ranged between approximately 2500 and 2570fps. I had been hoping for a little higher velocity, but I guess I'm glad I wasn't accidentally shooting super hot rounds.
--Winchester large rifle primers
--Once-fired Prvi Partizan Win 308 brass that had been shot by me in either the Rem 700 or my DSA SA58
--Brass was deprimed, full-length resized, and then trimmed to 2.015 with a Giraud.
--Cartridge OAL was roughly 2.820.
--Dillon 550B was used with Dillon rifle dies for resizing, bullet seating, and (light) crimping.
--Most primers showed some pressure signs, slightly flattened primers, but not much worse than some factory loads.
--All rounds were checked with a Dillon case gauge and found to easily slide in/out. Both ends of the cases fit inside the min/max steps on the case gauge.
--An RCBS precision mic was used to set headspacing on the resizing die. Headspacing length was measured on factory rounds before and after firing in the 700. I set the resizing die to ensure that cases were bumped back by 0.002-0.003 after being fired in the 700 (20+ rounds of factory Prvi Partizan 168 grain match)
Factory rounds cycled without problem through the gun, so I doubt there's anything wrong with the 700. Dummy reloads chambered fine. The bolt closed without much difficulty on the reloads, but got stuck after firing. Empty brass cases from fired reloads will not chamber without excessive force, as expected after having ripped them out of the chamber. I colored all over some fired cases with Sharpie marker and attempted to chamber them again in order to highlight wear marks on the brass. It looks like the only wear marks are light, appearing around the neck and then just behind the shoulder.
I've measured every critical dimension I can think of on the factory loads, factory load empty brass, reloads, and reload empty brass. Every dimension on the reloads is matched or undersized by a small margin. I have tried some reloads with head spacing set 0.002 below that of fired empty factory cases and other reloads set 0.005 below fired empty factory cases. I have also varied crimping between medium and almost non-existent. Modulating these two factors had no meaningful impact on anything I could detect.
The only interesting difference I have found between factory loads and my reloads is the brass case length after firing. Brass from factory loads doesn't seem to grow in length more than 0.003 during firing. However, my reload brass grows up to about 0.010 during firing. In other words, my brass is flowing a lot more on my reloads than it does on factory loads. Is there any way that this indicates why my fired brass gets stuck in the chamber?
Given my load data and velocities, is it possible that my loads are too hot? 43.0 grains of Varget should not be too high for this bullet, at least according to all the information I've collected from publications and also from other shooters. Lower charges do not seem to suffer less from the problem I'm experiencing here. What's going on????
