This could also be a headspace problem. If the bolt isn't able to close all the way then some of the energy from the firing pin spring is being used to "close the bolt". You then get a light strike of the firing pin. Check to make sure you have properly resized your brass.
redhawk
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Are you setting the shoulder back to much and making a head space problem ?
The cups on LP primers are shorter than LR primers so they will be counter sunk in the primer pocket of the cartridge case by an additional 0.010" [0.254 mm] So that will make lifht strikes worse. My IAI Auto Mag III (1911 style pistol) had a soft firing pin and the hammer mushroomed the end of the pin thus making it shorter and started light striking and failure to fire. Doesn't the 783 have the Savage style of collar? I don't own a Savage or 783 any possibility the nut loosened and changed headspace? (I have no experience with this system just an idea)
Firing pin protrusion generally falls in the .048 -.062 on most rifles.
The solid soft lead bullet is undoubtably the best and most satisfactory expanding bullet that has ever been designed. It invariably mushrooms perfectly, and never breaks up. With the metal base that is essential for velocities of 2000 f.s. and upwards to protect the naked base, these metal-based soft lead bullets are splendid.
John Taylor - "African Rifles and Cartridges"
Forget everything you know about loading jacketed bullets. This is a whole new ball game!
Have you been shooting full power loads or light cast loads. If not shooting full power loads , your headspace can increase with each firing ( shoulder getting shorter) and cause the issue you are seeing.
Also, if you have blanked/pierced a primer, the plug of primer could be jammed in the firing pin channel and restrict firing pin protrusion.
1) Check firing pin protrusion with bolt uncocked.
2) check headspace against a piece of fired brass fired with a FULL POWERED load. If you don't have the tool to do this, place a piece of pistol brass over neck/onto shoulder and measure thebentire length of the two pieces of brass together. If the current brass is significantly shorter (0.015+" then shoulder setback is your problem.
3) Check bolt throw travel to ensure the cocking ramp is not restricting striker travel ( Have you changed stocks recently. Make sure the bolt handle doesn't touch the bottomnof the bolt notch)
The gun should not all of a sudden stop shooting. I am betting shoulder setback on your brass feom shooting only light loads or excessive resizing/shoulder setback in the die(not as likely)
Refer to Larry Gibsons thread on drilling out primer pockets in mousefart loads to eliminate shoulder setback.
One last thing to try. PLEASE TRY THIS.
Put the rim of a loaded cartridge (or primed case) underneath the extractor and then insert into the chamber and attempt to fire it. If the issue is shoulder setback, doing this will headspace the case on the extractor (You cannot achieve this by placing the cartridge in the chamber and then closing the bolt) A cartridge headspaced off of the extractor should fire unless you habe excessive tolerances in this area.
Let us know what you find out.
OK. i just reread caliber and see that this is a 300wm/belted cartridge. It should not setback unless the chamber cut for the cartridge belt is out of spec.
Still doesnt mean that isn't the case. Though not nearly as likely.
I had a similar consistent light strike problem on a firearm I seldom shot. The firing pin channel was gunked-up impeding the pin’s forward travel, compounded by an over-stiff firing pin return spring. A thorough channel cleaning and a lighter return spring cured the problem. Now that firearm functions flawlessly even with hard magnum primers.
Not to split hairs but while the AMT Auto Mag III bears a passing resemblance to a 1911, they are built on different J. Browning operating systems. The absence of a grip safety, the slide mounted rotating hammer block safety and the slide mounted extractor of the AMT AM3 are the most apparent visible differences.
A bent hammer strut is a common cause of light strikes in an AMT AM3; don’t ask how I know.
The AMT Hardballer / Javelina are true 1911s.
Last edited by Bmi48219; 04-27-2023 at 12:40 PM.
I've had a problem with FTF on 2 different rifles from 2 different manufacturers within the last month. Both problems corrected with a new firing pin spring after confirming nothing else was out of spec or dirty.
Never had this happen before over 3 decades. It does happen without rhyme or reason.
Recently I fixed a local farmers Winchester model 70 which had started to misfire.
First thing was to check the length of the firing pin, using an empty case. After a couple of strikes, we examined the primer - it had a deep dent, indicating that the length was alright. We then took the bolt apart, cleaned the inside and gave it a few drops of thin oil - but no cigar!
I then made a number of washers to place under the spring to increase the striking force. This was literally barn work, using a chainsaw file and an angle grinder to modify some 6mm washers to fit the firing pin and fit inside the bolt. Once the job was done I pulled the bullet from a factory round (to eliminate any outside interference) and tested the rifle. It gave a very satisfying 'BANG' and left a perfect primer dent.
Compared to military bolt rifles, Hunting rifles often have a rather small "safety margin" when it comes to the force of the firing pin - especially with thumb-cooked rifles, like the Blazers. This is done to improve the ease of working the bolt and keep the necessary trigger pull weight down. After fifty years (with a permanently compressed spring) it's no wonder a rifle will sometimes misfire.
Cap'n Morgan
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |