Rifle blowing primers after Nitride

ShipAhoy

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I have a 22x47 rifle that shot fine for the first barrel. The second barrel shot 101 rounds perfectly before being nitrided, then after nitride it started blowing primers with 95 grain bullets. Under guidance from the builder, we tried reducing powder by 2 grains and went down to 82.5 gr bullets and still blowing primers. Done with this wildcat cartridge. The unnamed builder has no idea why this is happening.

I'd like to switch it to a 6.5x47 barrel. Any gunsmiths I can send it to for a barrel swap?

I won't mention the builders name because I do not want to give them bad press. Thx
 

THEIS

Hi, Sincerely
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  • Hi,

    Not sure how the builder would be getting any bad press.

    They built the rifle and it shot 101 rounds perfect right? That would pretty much rule out the builder being the issue.

    This is actually a perfect example of why nitriding should not be looked upon as an "aftermarket" treatment; it should be handled by the manufacturer and the manufacturer alone!!

    Have the builder slug the barrel and see what results he gets. Be willing to guess there are 1-3 "tight" spots.....

    Sincerely,
    Theis
     

    Bhobbs

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    Nitriding may build up on the exterior of the surfaces being nitrided. Depending on the application, it may have reduced the chamber and bore diameter enough to cause pressure spikes.
     
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    Evintos

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    Nitriding may build up on the exterior of the surfaces being nitrided. Depending on the application, it may have reduced the chamber and bore diameter enough to cause pressure spikes.
    Dimensional changes could be a growth up to 0.003" (or more; normally 0.001 to 0.002" if I remember correctly). If there is still a black oxide layer inside the bore, removing it with a weak acid (usually will not affect the surface hardening of the nitride layer) may remedy the situation by getting the bore diameter closer to original spec.
     
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    brianf

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    Dimensional changes could be a growth up to 0.003" (or more; normally 0.001 to 0.002" if I remember correctly). If there is still a black oxide layer inside the bore, removing it with a weak acid (usually will not affect the surface hardening of the nitride layer) may remedy the situation by getting the bore diameter closer to original spec.

    we are also talking about ID so its additive

    .002" application is a .004" smaller bore diameter etc...
     
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    THEIS

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  • Hi,

    Not all "Nitriding" is the same AND the firearms industry in general is beyond stuck in rut of continuing to utilize a nitriding method that is not optimized for our use.

    The 3 largest "nitriding" companies used in the firearms industry are still using Gas systems.....

    1626111962890.png


    Sincerely,
    Theis
     
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    357Max

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    I have a 22x47 rifle that shot fine for the first barrel. The second barrel shot 101 rounds perfectly before being nitrided, then after nitride it started blowing primers with 95 grain bullets. Under guidance from the builder, we tried reducing powder by 2 grains and went down to 82.5 gr bullets and still blowing primers. Done with this wildcat cartridge. The unnamed builder has no idea why this is happening.

    I'd like to switch it to a 6.5x47 barrel. Any gunsmiths I can send it to for a barrel swap?

    I won't mention the builders name because I do not want to give them bad press. Thx
    Yeah that was a bad idea, but you already know that.
    After 101 rounds I'm sure there was some fire-cracking in the throat. Nitrite doesn't just build up .001-.002 it also penetrates. Probably would result in more build in the throat.

    You could turn your neck down -.002 on a few pc's of brass and go after the chamber/throat with this. I have doubts it will shoot well but might solve the blown primers.

    egay
    1626116351683.png
     

    ShipAhoy

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    I don't want to use this 22x47 barrel. I want to switch the gun to 6.5x47 Lapua and need a gunsmith to install a new barrel. Thank you.
     

    b6graham

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    Action is needed

    But you can get a prefit for just about anything from dozens of different smiths
     

    BurnOut

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    Just gonna throw this out there... Small Rifle Magnum primers. The thicker cup resists piercing. Of course, the wisdom of this assumes that you're not getting other pressure signs... but try this at your own risk, obvs.

    I stumbled across this as a solution when I was piercing regular Small Rifle primers well below Hornady listed max loads on a .204 Ruger (MV was where it should have been for those loads and there were no other pressure signs, so it's not like I was unknowingly running them hot).
     
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    diggler1833

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    I bought a nitrided gas tube made by a reputable manufacturer for a large frame AR build...it was completely obstructed on the inside and turned my rifle into a single shot until I figured it out.

    I'm not saying that the nitride process caused a buildup somewhere that is creating pressure...but I am saying that I wouldn't count that possibility out.

    I bet that the barrel swap results in a perfectly fine 6.5x47.
     
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    RTH1800

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    I have a few thousand .19 caliber bullets I’ll cut loose if you have interest. 😂
     

    Satterlee

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    I built a 7wsm that was a very accurate rifle right up to nitride. 1/8 to 1/4 sub 1/2 gun.
    After nitride I was blowing primers, speeds down by 150fps accuracy screwed, 1-1/4, groups, total garbage for groups.
    Cases sticking, hard extraction with mild loads.
    After about 50 rounds worth of screwing around I put my bore scope in the bore and what I discovered was interesting and horrifying.
    The 1st 1.5 inches of the bore back from the muzzle was pitted badly like the surface of the moon, same deal on chamber, pitted and rough as hell.
    Clearly the nitride entered the bore from each end, but why didn't it go all the way thru the bore, I'm guess an air pocket prevented that.
    Fix, I set up and took 2.0 inchs off the length with got me out of the rough stuff on the end of the barrel. On the other end I judiciously polished the chamber.
    Hard extraction gone, guess that only makes sense, no longer forming brass into pits.
    Accuracy? Well kind of I guess, I've ran few 5 strings into 5/8 with it but I haven't gone less than 1/2 with it since nitride.
    I've build rifles for 35 years, nitride has it's place, rifle barrels not being one them.
    Will not go down the nitride on a rifle barrel road again.
    In retrospect a treatment that was supposed extend the barrels life turned it to shit inside of 150 rounds.
     
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    Totoro

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    I took a gamble once having a PacNor 223 SAAMI spec chamber for p'dogs nitrided.

    I took me a total of 5 shots to find out it was a waste of $$.

    Maybe it was the application or prep process, who knows, but in the end my money goes elsewhere.
     
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    Tokay444

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    Guys. Guys. Op is just looking for a gun smith to chamber and thread a new barrel. I know the title is misleading, but that’s all he wants.
     
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    larryh128

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    1st thing you need to do with a SBN barrel (salt bath nitrided) is scrub the living hell out of the barrel ID. WITH brushes a lot. SBN leaves a residue that needs to be removed. Once it is there really shouldn't be any difference. I shoot a shitload of nitrided barrels, everyone of them needs to be scrubbed. Barrels should be nitrided before shooting. Nitriding won't kill barrel accuracy. Your chamber could also be full of gunk. I've heard a lot of stories about nitrided barrels not shooting. Cleaning cures it. A LOT OF CLEANING until the patches aren't black.
     

    THEIS

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  • 1st thing you need to do with a SBN barrel (salt bath nitrided) is scrub the living hell out of the barrel ID. WITH brushes a lot. SBN leaves a residue that needs to be removed. Once it is there really shouldn't be any difference. I shoot a shitload of nitrided barrels, everyone of them needs to be scrubbed. Barrels should be nitrided before shooting. Nitriding won't kill barrel accuracy. Your chamber could also be full of gunk. I've heard a lot of stories about nitrided barrels not shooting. Cleaning cures it. A LOT OF CLEANING until the patches aren't black.

    Hi,

    AND none of that would be necessary if the firearms industry would actually utilize the correct process instead of the cheapest process.

    Sincerely,
    Theis
     

    Totoro

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    As for riflesmith to screw in a new tube, any of the riflesmiths on the 'hide or a host of other reputable riflesmiths around.

    DST, GAP, LRI, etc
     
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    Greg Langelius *

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    I have a CMMG Bull W.A.S.P. Upper which uses this coating process. But I don't see it in the barrel and assume the coating was done before the bore was finished.

    It shoots very well. I consider it (at 16") to have a consummate urban sniper potential (Day-Dreaming in the focus of the mind's eye...).

    As I understand the original discussions here about phosphate coating, there was talk (I never figured out if there was proof) about dimensional buildup from these coatings, and that astute manufacturers were adjusting bore, etc., dimensions to make allowance for that. There may be some of that here.

    Greg
     
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    larryh128

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    I have a CMMG Bull W.A.S.P. Upper which uses this coating process. But I don't see it in the barrel and assume the coating was done before the bore was finished.

    It shoots very well. I consider it (at 16") to have a consummate urban sniper potential (Day-Dreaming in the focus of the mind's eye...).

    As I understand the original discussions here about phosphate coating, there was talk (I never figured out if there was proof) about dimensional buildup from these coatings, and that astute manufacturers were adjusting bore, etc., dimensions to make allowance for that. There may be some of that here.

    Greg
    Quality nitriding doesnt add any dimension, its a hardening process. Dimension added after SBN is lack of cleaning the sludge out.