Savage barrel thread engagement

M

mikendi

New member
I am building a 300wsm on a Savage target action that was a 223. My question is because the bolt head on the 223 is about .435 thou. thick and the 300wsm bolt head is about .568 thou. thick I am going to have about .138 thou less threads screwed into the action, Is that enough to hold the pressure from 300wsm.
The Lady at Savage said that is what the Weather Warior has????????
Any in put is appreciated. Thanks
 
Many target actions have been converted to mags with no problems, I have done at least 12 myself with no issues.
 
Jim, Is .563 enough for the Mag pressure, it probly will be but I was asking someone like yourself that might have done the Mag conversion. I have rebarreled probly 100 barrels with the standard thread engaugement of about .800 thou. But never with a lesser thread engaugement.
 
I measured a Savage LRP action from the receiver ring to the lug seats and that was 1.155" and .655" of that is threaded for a difference of .500" so you have .655" of thread engagement for a .223 and roughly .575" thread engagement with the 300WSM bolt head, or only .080" less engagement. - nhk
 
nhkuehl, Here's the mic measurements from the rifle I am working on. The 223 from the face of the action to the bolt face is .703<> the 300wsm measures .565. So I have 138 thou less threads in the receiver. Just thinking about the pressure of the mag and less receiver holding the pressure.
 
Isn't there a little gap between the bolt head and the threads where there is no engagement anyways? - nhk
 
I leave about 3 to 5 thou between the bolt face and the barrel. I chamfer only about 1 thread, not 1/8 on an inch like recommended. This is to gain barrel/receiver contact.
 
You have me somewhat confused..

The bolt face diameter has no relationship to the tenon thread length in an action. Since Savage uses an independent bolthead there may be a few thousands difference but not enought to make a differance as far as safety goes. You will have to cut the tenon length to accept a shoulder fit or barrel nut fit so their is between .003 to .010 boltface/tenon clearance. The tighter you make it the cleaner you will have toi keep your gun. I like keeping hunting guns between .008 and .010. Otherwise temperature and little trash can put an end to your shooting in the field. The headspace is set in a different operation and it is adjusted using headspace gauges. SAAMI spec puts it into a .0035 specified range.

Savage rifles even the target models will accept multiple bolt heads. You should inspect and adjust them for bilateral lug engagement, and primary extraction when you change bolt heads.
Nat Lambeth
 
Rustystud said:
The bolt face diameter has no relationship to the tenon thread length in an action. Since Savage uses an independent bolthead there may be a few thousands difference but not enought to make a differance as far as safety goes. You will have to cut the tenon length to accept a shoulder fit or barrel nut fit so their is between .003 to .010 boltface/tenon clearance. The tighter you make it the cleaner you will have toi keep your gun. I like keeping hunting guns between .008 and .010. Otherwise temperature and little trash can put an end to your shooting in the field. The headspace is set in a different operation and it is adjusted using headspace gauges. SAAMI spec puts it into a .0035 specified range.

Savage rifles even the target models will accept multiple bolt heads. You should inspect and adjust them for bilateral lug engagement, and primary extraction when you change bolt heads.
Nat Lambeth
Click to expand...

Another thing that can be done, is to eliminate the barrel nut when you cut a barrel fo a savage. Just set up the bolt with the proper bolt head (Magnum .535 in this case). Put the bolt in the action, take the measurements for tenon length and headspace, and cut and chamber the barrel as if doing a remington or the like. This barrel will now not need the nut, and will always use the same bolt head anyway. From this point forward there is no guesswork to setting headspace with this configuration.

Paul
 
Rusty Stud, It is thickness difference of the 223 bolt head and the Mag,, The 223 just screws into the receiver deeper than the 300WSM does by about 138 thou.. I almost always fit the barrel with a shoulder like a Remington, I like it better. I will try it Thursday and will give a report then. Thanks
 
Making a shoulder fit tenon..

Measure the diatance from the action front to the bolt front. Add the thickness of the recoil lug. Subtract .010. This is the length from the tenon face to the shoulder. Most Savages have .0117-.0123 from the bolt front and the bolt face. I make my barrels fit leaving me .008 to .010 gap between the tenon face and the bolt front. Then I can headspace using the go and no go gauges. I have only left .0015 gap but when the action heats up the bolt may freeze up. Any trash will cause the bolt to freeze up. At least .005 is my usual minimum.

Nat Lambeth
 
To answer the op's question concerning thread engagement and what is enough, I do believe Harold Vaughn showed in his book that only 3 threads are really doing anything anyhow, so much past the 4th revolution is just along for the ride.

By the time a bolt has 3/4 of it's diameter engaged as thread, there's more thread strength than there is bolt strength. When considering a barrel, we never think of one breaking off at the shoulder due to torque or tensile load, but then, I've never heard of anybody stripping the threads on one either.
 
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