Bolt interchangeability

[fguffey]

The man I purchased the mill from, he had a box of go, no and beyond gages, he took them out and handed them to me, and I ask????? “You know the bolt closes on the go-gage?” “You know the bolt will not close on the no go-gage?” “You want to know the length of the chamber in thousandths?” Again, the length of his chamber was .0075” longer than a minimum length case, he had a new, over the counter, unfired box of 20 Remington ammo, we checked the length of his new ammo from the shoulder to the head of the case, total spread .0005” and that ‘my friend? is better than his box of head space gages. Then to explain the box of gages, the man that gave them to him measured the gages and proclaimed “I can do better than that!”

Back to “driving me into the curb” A go-gage can be converted to a go to infinity-gage, but, there just does not seem to be anything beyond talking about it.

F. Guffey

[mhb]

What we have here is a failure to communicate.
I addressed you directly because you took exception to something I posted in clarification of one of the responses to the original question which started this thread.
I believe my answers to that original post were concise, accurate, and sufficient to satisfy the original poster's need for information, and that the added comments on the suggested ad-hoc headspace test were appropriate, also.
Having carefully re-read (again) all that you have contributed thusfar, I have to say that I can find no added value to the original discussion - neither can I determine what pertinent points (if any) you were trying to make. I believe there is no point in continuing this particular exchange.
And, FWIW, I do have a copy of Hatcher's Notebook - but none of Hatcher's experiments under controlled conditions can be taken as an indication of assured safety to the average shooter who controls few, if any, of the many variables in the arms and ammunition he uses.
If you still feel it necessary to continue with this thread, please address your remarks to one of the other posters: I have nothing further to add, and no interest in argument for its own sake.
mhb - Mike

[daveboy]

Interesting....

[Tom]

Hey guys, on my hunting rifles (1903A3) the bolts are nicely modified for the scopes. The bolts "origin and vintage" cannot be seen because of the handle change. They could even be pre 1918, I'll never know. I recheck the headspace now and then. It is always good with the go and no-go gauges. No worries??

FGuffey said that an 03 bolt has a different measurement on one of the lugs, than the same lug on an 03A3? I would like to determine the original bolt type, from this measurement, if you could explain how to go about this. Thanks Tom.

[mhb]

are functionally interchangeable. The dimensional difference referred to is the clearance allowed between the safety lug and the rear receiver wall: in the 1903, the minimum permissible clearance is .004". The A3 bolts were manufactured to give a much larger clearance at the same point, but, in neither case should the safety lug ever contact the receiver wall - it is only intended to prevent the bolt from being blown rearward out of the receiver in the event both forward locking lugs fail (and does serve somewhat to steady and guide the bolt in its movement).
In addition, the A3 bolts are generally much more roughly machined, and have an area of visibly smaller diameter around the safety lug as a result of simplified machining, while 1903 bolt bodies are smooth for their full length.
If you have any doubts about the bolts in your rifles, some photos should allow them to be identified (roughly) as to original type, as would any markings remaining on the bolt handle root or safety lug.
mhb - Mike

[fguffey]

Hey guys, on my hunting rifles (1903A3) the bolts are nicely modified for the scopes. The bolts "origin and vintage" cannot be seen because of the handle change. They could even be pre 1918, I'll never know. I recheck the headspace now and then. It is always good with the go and no-go gauges. No worries??

FGuffey said that an 03 bolt has a different measurement on one of the lugs, than the same lug on an 03A3? I would like to determine the original bolt type, from this measurement, if you could explain how to go about this. Thanks Tom.

FGuffey said that an 03 bolt has a different measurement on one of the lugs, than the same lug on an 03A3? I would like to determine the original bolt type, from this measurement, if you could explain how to go about this. Thanks Tom.[/QUOTE]

There is period correct, a different question, then there are replacement bolts, I do not have less than 30 Springfield bolts, most are (new) replacement bolts, I have two boxes of Brown and Sharp replacement bolts with two bolts in each box, logic? would suggest the two bolts would be different when off setting the length of the chamber, did not happen, both bolts are the identical .

Difference? The replacement bolt’s (exposed) third safety lug is forward of the third lug on the original 03s, Again, had Springfield and or Hatcher noticed the third lug and the gap between the rear of the lug and the rear receiver ring (sight bridge on bolt set-back could have been monitored from the beginning. The gap could have been established and monitored from the beginning, Again, the gap is smaller on the older 03 bolts than on later bolts.

It would make little to no sense to build a replacement bolt with close tolerance if the bolt was to be built to replace and fit any 03 from Springfield and or Rock Island to Remington A3 and Remington 03A3 and Smith Corona.
From the beginning the gap could have been used as a tool, today the gap can be used as a tool for a 03 owner, for a small investment of $11.00 +/- $5.00 the owner of an 03 type Springfield can measure the difference between the length of a go-gage and the chamber, O have head space gages, I make go gages, I do not shoot head space gages, I shoot ammo, I use the gap between the rear of the third safety lug and front of the rear receiver ring when deterring the difference in length between the chamber and case from the shoulders to the bolt face and shoulder of the case to the head of the case.

Then there are bolts used at arsenals by smiths that are know only in pictures, I have one that is stamped Bonny Forge.

Again, I have little interest in knowing if a go-gage will allow the bolt to close, I have little interest in knowing if the bolt will close on a no go-gage, anyone with an understand of a micrometer and it’s use can determine the length of a chamber on an 03 with just a field reject gage.


http://www.vishooter.net/m1903.html

F. Guffey

[chuckindenver]

if you have a couple sporterized hunting rifles based on the 1903, and the bolts have worked and gauged ok, for years, i dont see them changing..
check them now and then, and always look for signs of pressure or headspace issues on your fired brass.
deal with the issue as it comes up.

[keith smart]

check them now and then, and always look for signs of pressure or headspace issues on your fired brass.
deal with the issue as it comes up.


AMEN

[Tom]

`My gosh!!

--The FIRST rifle is a correct SC, not modified. I pulled out of my safe, has the "square safety lug",and it has a "huge gap" between rear of safety lug, and the front shroud on the rifle. (I can easily stack 4 business cards together and they will fit into the space,.

--The SECOND rifle is same set-up (correct SC) non modified. Again, need 4 business cards to fill the gap.

--The THIRD rifle SC hunting rifle, with modified bolt. Again, need 4 business cards to fill the gap.

--The FOURTH rifle is Rem 1903A3 hunting rifle, WE HAVE A PROBLEM. "NO business cards" can get into the slot, it is metal-to-metal. Now it has even FAILED head spacing. It will close on both head space guages. So, I assume the bad H.S. is because there is no gap, and the safety lug is riding, back, against the front of the tunnel??

So what should I do about this last rifle?. I have a box of about 10 bolts, some are new Smith Corona (with the x), but I may even have another mod bolt.

I'm going to the club tomorrow and was going to shoot a bunch of my guns, so maybe I'll put a new bolt in, then H.S.it.

[mhb]

By all means try another bolt (or bolts) in the rifle with excess headspace. If the safety lug is actually bearing on the receiver, the locking lugs are likely very worn, or have been modified - they may not be in contact with the lug seats in the receiver at all. Remember, though, that the 1903 bolts were supposed to have a minimum of .004" clearance with the receiver, and that business cards are considerably thicker than that. What you need to check the clearance properly is a feeler gauge. In any case, if the bolt closes on the 'No-Go' gauge, you should try to correct that condition, and the safety lug must not touch.
If the safety lug is in contact, it is a result, not the cause of, the excess headspace condition.
mhb - Mike

`My gosh!!

--The FIRST rifle is a correct SC, not modified. I pulled out of my safe, has the "square safety lug",and it has a "huge gap" between rear of safety lug, and the front shroud on the rifle. (I can easily stack 4 business cards together and they will fit into the space,.

--The SECOND rifle is same set-up (correct SC) non modified. Again, need 4 business cards to fill the gap.

--The THIRD rifle SC hunting rifle, with modified bolt. Again, need 4 business cards to fill the gap.

--The FOURTH rifle is Rem 1903A3 hunting rifle, WE HAVE A PROBLEM. "NO business cards" can get into the slot, it is metal-to-metal. Now it has even FAILED head spacing. It will close on both head space guages. So, I assume the bad H.S. is because there is no gap, and the safety lug is riding, back, against the front of the tunnel??

So what should I do about this last rifle?. I have a box of about 10 bolts, some are new Smith Corona (with the x), but I may even have another mod bolt.

I'm going to the club tomorrow and was going to shoot a bunch of my guns, so maybe I'll put a new bolt in, then H.S.it.