Marine Springfield Bases

[Marine A5 Sniper Rifle]

There are only two Winchester sets of bases for the #2 (and #1) mounts to my knowledge. One set of bases will mount an A5 on 6" centers with the rear flat bottomed base set on the rear of the '03 fixed rear sight base, and the other set (Marine Springfield bases) will mount an A5 on 7.2" spacing with the rear curved bottom base mounted on the receiver ring. I know of no other bases for the Winchester #2 mount. One might ask why the different spacings. Based on what I have read, the 6" spacing preceded the 7.2" spacing, but it really makes little difference. Out to a bit less than 1,000 yards, the 7.2" spacing has the advantage of simplifying windage adjustments (1" impact movement at 100 yards, 2" impact movement at 200 yards, etc). But at 1000 yards, limited field of view causes sighting problems as to elevation (keeping the crosshairs on the target). At this point, the 6" spacing has the advantage due to greater vertical movement per incremental "click".

But why mount the rear base on the receiver? Simple. If you have ever D&T'ed an '03 barrel as I have, you know how thin the barrel wall is at the location for the front mount on 6" spacing. If you go to 7.2" spacing by moving the front base forward, the barrel wall thickness is a very serious issue for a good D&T. The obvious solution is to go the other way, and put the 7.2" spacing rear base on the receiver. Problem solved.

As soon as scopes were allowed in matches, Winchester would have made the necessary bases available to the public. I think they started with the 6" spacing. It probably took the military match shooters and coaches a few days to realize the advantage of 7.2" spacings, as time is of an essence in matches. Again, from what I have read and seen, both spacings were being used on '03 match rifles as early as 1914, and I suspect a lot earlier. Both were available in 1916. The 7.2" spacing was used on non-'03 commercial and match rifles even earlier.

Since the width and length of the scope base is determined by the internal shape of the mount receptacle (the part that touches and clamps onto the base), the only variant for any given mount and spacing is base height. So my question is, does anyone know of any set of commercial Winchester bases for mounting the Winchester #2 mount on 7.2" spacing on a 1903 Springfield other than the bases I have discussed?

jt:1948:

[JWM]

Winchester scope bases...always an interesting and confusing subject. As I understand it, the length of the scope had a great deal to do with the spacing of bases according to early match shooters and noted by one author, Senich, on page 3 of his book U.S. Marine Corps Scout-Sniper. Interestingly, the 03 rifle presented on the same page and, again, on the following page, apparently has a forward base of probably two plus inches in length if one can believe these pictures. Winchester commercial? I can't say for sure...possibly so, though, especially when the following info is digested, along with the length of scope and eye relief being taken into consideration when 1 and 1/2 inches would be ideal for obtaining a maximum field of view.

According to Winchester, "No definite location of bases for telescopic sights can be given because of the different dimensions of guns, stocks or normal holding position of individuals."

James

[1903fan]

I guess I'm sort of confused, so the Marines were using the tapered block mounts and then went to Winchester #2 mounts and then went back to the tapered mounts almost immediately?

[Marine A5 Sniper Rifle]

Winchester scope bases...always an interesting and confusing subject. As I understand it, the length of the scope had a great deal to do with the spacing of bases according to early match shooters and noted by one author, Senich, on page 3 of his book U.S. Marine Corps Scout-Sniper. Interestingly, the 03 rifle presented on the same page and, again, on the following page, apparently has a forward base of probably two plus inches in length if one can believe these pictures. Winchester commercial? I can't say for sure...possibly so, though, especially when the following info is digested, along with the length of scope and eye relief being taken into consideration when 1 and 1/2 inches would be ideal for obtaining a maximum field of view.

According to Winchester, "No definite location of bases for telescopic sights can be given because of the different dimensions of guns, stocks or normal holding position of individuals."

James

I don't have Senich's book in front of me right now, but scope base spacings do depend on a lot of factors. Externally adjusted scopes like the A5 have more limitations than the internally adjusted scopes, which have few limitations. Barrel thicknesses, types of receivers, open versus closed receiver bridges; all play a part in where to place bases. Speaking only of the externally adjusted A5 scopes, I believe the 6" spacing may have been the way to go initially for Winchester due to ease of installation. Target shooters are a pretty finicky bunch, it is wouldn't have taken more than a few matches before the "1 click = 1 MOA" simplification of scope adjustment in the heat of a match would have become predominant. The limited field of view of the A5 and adjustment limitations for really long matches such as the 1,000 yard and 1,200 yard matches would have guaranteed the 6" spacing rifles a slot in the match rifle rack. One Marine shooter used the same 7.2" spaced A5 scoped rifle in both the 1912 and a post war match. That the Marines used both spacings as early as 1911 or 1912 is not at all surprising. What would be surprising would be their NOT using both spacings. The Marine match shooters were the most savvy shooters in the world, and were exposed to other rifles in the various matches they attended, including international matches. Very early cars had three wheels, but it took a few years to jump the design gap to four wheels. So how long for the best gunners in the world to think about "1 click = 1 MOA" and switch to 7.2" spacing? That time would have been measured in days or weeks and certainly not a decade. The idea that the mounts for the 7.2" scope spacing didn't come about until WWI is just ridiculous. And the 7.2" spacing bases for the unmodified #2 mounts ARE the "Marine Mounts".

The statement by Winchester is correct, but they weren't speaking specifically of the A5 mounted on a 1903, they were including the entire world of firearms.

jt

[Marine A5 Sniper Rifle]

I guess I'm sort of confused, so the Marines were using the tapered block mounts and then went to Winchester #2 mounts and then went back to the tapered mounts almost immediately?

Are you referring to the bases on the sniper rifles or the various match rifles? Referring only to the WWI Marine sniper rifles, my position is that all the Marine sniper rifles had Mann-Niedner bases, and the position of the other side, as far as I can discern, is that the first 150 rifles had Mann-Niedner bases and the remainder had clamp-on Winchester 7.2" spacing bases. Each of us claims we can prove our assertions, me by physical photos and documents, and them by documents they say they pulled from the archives. I have photos of a group of sniper students, and instructors, taken after they were issued their rifles; and they all have Mann-Niedner bases (with 8-loop scope cases). Take your pick.

jt

[1903fan]

After reading though all the posts it seems more likely to me that they were all using Mann-Niedner bases. It makes more sense that they would use what works.

I might be missing something, but is the "tappered bases" the same thing as tapered bases? I've seen a few posters use that phrase, and am afraid I might be missing something! Like the old saying in Tennessee, "fool me once shame on you, fool me can't get fooled again!" :eek:

[Randy A]

marine A5 Sniper, sent you a time sensitive PM that includes Winchester mounts.. maybe, check it out, ends tomorrow (Tuesday).

[Promo]

Since it's over now anyway, would you share what you meant?

[Marine A5 Sniper Rifle]

marine A5 Sniper, sent you a time sensitive PM that includes Winchester mounts.. maybe, check it out, ends tomorrow (Tuesday).

Thank you, Randy.

jt

[Marine A5 Sniper Rifle]

After reading though all the posts it seems more likely to me that they were all using Mann-Niedner bases. It makes more sense that they would use what works.

I might be missing something, but is the "tappered bases" the same thing as tapered bases? I've seen a few posters use that phrase, and am afraid I might be missing something! Like the old saying in Tennessee, "fool me once shame on you, fool me can't get fooled again!" :eek:

They are the same, just alternate spelling.

As to what was used, those doing the ordering would have settled for nothing less than identical rifles. It will all come to light in the near future. I have decided to publish what I have on the forum, but the best format eludes me. It is a huge document. I have endeavored to keep people from buying fakes for years, and was reluctant to publish anything that would help the fakers. Others are not so inclined.

jt

[Kragrifle]

Late joining this discussion, but I always thought the 6 inch spacing was Winchester and the 7 1/2 inch spacing was for the longer Unertl scopes.

[Marine A5 Sniper Rifle]

Late joining this discussion, but I always thought the 6 inch spacing was Winchester and the 7 1/2 inch spacing was for the longer Unertl scopes.

The scope spacing had nothing to do with Winchester, or SA for that matter. Scopes had been around long before either got into the game. I suspect the 6" spacing originated due to ease on installation of the bases. The flat area of the FRSB was convenient, and one can only go so far down a 1903 barrel before wall thickness becomes a problem. The 7.2" spacing is common for externally adjusted scopes since it makes bullet impact movement calculations quite simple (1" at 100 yards is approximately 1 MOA with 7.2" spacing). This is an issue only because the A5 is an externally adjusted scope.

The real issue in this discussion is the difference between a Marine Mount (the part that holds the scope), and a Marine Base (the thingee attached to the rifle to which the Mount attaches). The Marine Mount is the highly modified #2 WRA scope mount with large dials and pointer you see on the WWI Marine A5 sniper scopes, which some seem to confuse with the Marine Base as shown in the 1928 WRA drawing shown in Brophy. The Marine Base is the set of bases required to mount a non-modified #2 WRA mount on a 1903 Springfield using 7.2" spacing. The Marine Mount uses Mann-Niedner tapered bases. Very simple, really.

Jim

[1903fan]

I'd go out on a yonder limb and wager that people often try to prove rifles they already have, and that is what influences the conclusions they come to.