Bolt interchangeability

[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]

Tom:

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.

[fguffey]

`My gosh!!



--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.

“--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”

The ‘no-gap’ is caused by the location of the third lug, again, older bolts have the set-back third lug. Business cards, there is a micrometer that counts paper sheets in a stack, it also works for business cards, I use the feeler gage, from the beginning it has been called a ‘thickness gage’ $5.00 + a little from Harbor Freight, $11.00 from other suppliers.

The Problem! The third lug is a JIC thing as in just in case something goes wrong with the front lugs, if the third lug is supporting the bolt there is a chance the two front lugs are not supporting the bolt, POINT? The third/rear/safety lug must not contact the rear receiver ring.

Changing the bolt to a replacement bolt as in the 10 +/- bolts in your bucket, by description they are replacement bolts meaning the third lug/safety lug is not set back. Again, when replacing the bolt it is possible to determine the effect each bolt has on off setting the length of the chamber with a go-gage and or ammo that is going to be fired if the person doing the testing has a feeler gage/thickness gage.

Chamber the go-gage, pull the bolt back to seat the lugs, then measure the gap, in thousandths, between the third lug and front of the rear receiver ring, then push the bolt forward and measure again, the difference between the two readings indicate the difference between the length of the gage and the length of the chamber. Or, use the ammo that is going to be fired, ME? I do not shoot gages, I shoot ammo.

If there are any reloaders among members of this forum it gets easier, All of my presses and dies have threads, threads make it possible for me to adjust my dies to the shell holder making it possible to control the length of the case from the shoulder of the case to the head of the case, meaning I size cases/form cases that are for short chambers, I size/form cases for long chambers. For short chambers I form cases that are .012” shorter than a minimum length case, I form cases for chambers that are measured to be .002” longer than a field reject chamber, that is 28 different length cases separated by .001” each. Point? Head space gages come in three lengths.

F. Guffey

[chuckindenver]

something everyone has over looked.
modified bolts,.. EA.. turned down to clear a scope...some are done right, and whoever did the work had skill.
however.
most iv seen, were done by someone with a hammer, grinder and a torch. no heat sink. ect.
a warped or distoreted bolt forced into a rifle can destroy the locking weighs...
without having the rifle in my hands...anything at this point would be like the rest , a shot in the dark.

[fguffey]

Chuck in Denver, he did not say the bolt handle was binding, dragging and or touching the rear receiver ring, plus there is nothing about the bolt handle that can cause the bolt to be pulled to the rear and shorten the gap.. Again, I said it is possible to measure a bolt to determine the effect it can have on the length of the chamber from the shoulder of the chamber to the bolt face. I also said I am hard pressed to find someone can make that measurement.

The M1917 Enfield is a British design, it does not have the third Mauser lug, the M1917 uses the bolt handle (root) for the (JIC) safety, when modifying the bolt handle on the M1917 it must be fitted if the bold handle is cut off at the bolt body. But ‘if’ the leaver policy is applied the root of the bolt handle on both rifles will not change the configuration.

”...anything at this point would be like the rest , a shot in the dark”

Leaver policy: In these matters I apply the leaver policy, I leaver the way I founder.

I have 03 type bolts that have a drilled and tapped hole through the root of bolt handle.

Third Mauser lug: The third Mauser (safety/JIC) lug is not exposed when the bolt is closed, when modifying the bolt handle on the 98 type Mauser the bolt handle does not touch the rear of the receiver ring until it is raised, when raised, the bolt cams back.

F. Guffey

[fguffey]

and he said he had a bucket of 10 bolts, he also said he thought one of them had a modified handle, “anything at this point would be like the rest , a shot in the dark” in my way of thinking that gives him 9 shots in the light and one chance he will not find it necessary to remove the scope. I have nothing against this the owner of the Springfield knowing everything there is to know about his rifle.

F. Guffey

[Tom]

Thanks guys. I have removed the questionable bolt. I went through my bolts and installed another one (S/C). It is very hard to get it through the tunnel. No other bolt would go through the tunnel, not even with a rubber hammer. But now this one is in now and headspaces good, and I have a gap between lug and and receiver.

The bad bolt appears to have modified front lugs, they are filed down sorta. Not from wear, but I see file marks. I will add pictures tonight.

It's 80 degrees out, coyotes are out, and I'm heading to my secret spot in the desert. The one in my little picture.

[fguffey]

Through the tunnel, also know as a rear receiver ring, then there is another name, on some rifles the rear receiver ring is referred to as being the rear sight bridge. If the bolt is having trouble when installing check for screws that are too long, the screws will be holding the scope mounts to the receiver. If your bolt has been filed/altered the person that installed the scope mounts could have thought it necessary to grind the bolt, a better choice would have been to use shorter screws.

F. Guffey

[Tom]

Thanks fg, Ya, I know what it's called, but I'm thinking of new people who would be lost like I was for so long, before I bought books.

Problem is not the screws, they do not extend through. Perhaps the rifle has been dropped and the rear sight bridge is crushed. However, the forward lugs are already through that area, upon binding. Wish I had time now for pictures. I'm going to shoot this rifle today and see where the blueing wears. Tom

[fguffey]

Forgive, then comes the/another consideration, a friend gave me a M38 Turkish Mauser, we both know where the rifle came from, there was no way a bolt could be installed, I informed my friend the owner attempted removing the barrel with a block stuck through the receiver, he twisted it, I said something like “all that is required to straighten it is a set up table etc., “, anyhow, he kept the receiver, straightened it then installed a new 6.5mm55barrel.

If your bolts will not install consider the receiver is twisted, or crushed?

F. Guffey

[chuckindenver]

this rifle has more issues then a bolt and headspace.
post a picture...lets see it..
without having the rifle in my hands...it would be a waste of time.

[Tom]

this rifle has more issues then a bolt and headspace.
post a picture...lets see it..
without having the rifle in my hands...it would be a waste of time.

I think we've taken over the original poster's post. My apologies to Marine from Virginia.

Photo 1. Modified bolt rides against the rear receiver ring. No gap. (ejector is removed for photo).
Photo 2. Same
Photo 3. New bolt does not ride on the receiver ring. (Plenty of gap)(four business cards).
Photo 4. Side-by-side view of front of bolts. Do we see the cause of headspace problem?
Photo 5. SA extractor, was just wondering what the punch-marks mean.

"Click-on" photo to enlarge.