CMP/Criterion replacement Krag barrels...

[mhb]

I've been shooting Krags for many years, but have never yet found one with a good bore that actually had a nominal groove diameter (.308"). In fact, those I've been shooting run between .309" and .311", and, while they shoot quite well with appropriate-diameter bullets, I can't help but feel that the best performance would come from one of the many, more readily available .308" bullets in a correctly-proportioned bore.
When CMP announced the availability of their Criterion barrels, I rejoiced, and, trusting in the reputation of Krieger (who then operated Criterion as a subsidiary), ordered 2 of them.
I was sorely disappointed with them on several counts:
1: the bore diameter of both was .302" (which is not necessarily a show-stopper, and is not uncommon in button-rifled barrels), but the groove diameter was a full .309" - no better than my originals.
2: while the barrels were correctly threaded, index-marked, and had the front sight base dovetail and rear-sight screw holes located and milled/drilled, the front sight base was not attached (would have to be provided and installed by the purchaser) and the screw holes were not for the original thread.
3: though the barrels were described as 'short chambered', they were in fact fully chambered, and as large in every dimension as the original military chambers, readily accepting any original Krag cartridge I tried in them. Had they been actually rough-chambered, I'd have been able to finish ream them with a match reamer and throat them separately for the bullets I intended to use.
After determining all these things, I decided not to use them, and sold one of them ( I still have one).
I actually contacted the production manager at Criterion, and he was unable to provide satisfactory explanation of any of the problems named.
So...
Who has actually used any of these barrels, and with what results?
Thanks;
mhb - Mike

[keith.herrington]

Could not disagree more

My experience has been very, very positive. Bought one about a year ago and had my gunsmith, David Sams, install it for me. He did his usual brilliant job. The sights are even perfectly regulated in both elevation and windage for full power 220 grain loads. I have not slugged the bore but have had excellent results at the range using RN Sierra, Hornady, Lapua and Nosler bullets in the 200-220 grain range.

This is one of my best groups using the Sierra 220 RN over 41 grains of IMR4350 lit by a CCI 200 primer. The new WW brass was trimmed and chamfered and sized before loading.


This group was the Hornady RN 220 grain over 41 grains of IMR4350.


All shooting was from 100 yards using a bench and a sandbag rest under my non shooting hand.

The gun is shown below. Except for the new barrel (which looks identical to the original) the gun has not been modified in any way, but is original throughout.


To get it all done the way I wanted was a bit pricey but I could not be happier with the results and its performance. It's not an easy gun to shoot accurately due to the crude sights but as I learn its little quirks, the groups get smaller.

[Parashooter]

The rifle appears to have the model 1901 rear sight. While it's adjustments are certainly less precise than those of a good micrometer receiver sight, the sight picture offered by the small aperture and fine post is about as precise as any you'll find on an iron-sighted military rifle - and far from "crude". If anything, the 1901 sight picture is too refined for those of us with less-than-perfect vision or older eyes that cannot shift focus rapidly.

If you have difficulty using/seeing the aperture and post, you may need an eyeglass lens specifically made to focus just a bit beyond the front sight - or you may find it helpful to ream the aperture larger and/or install a wider front blade. (CMP match rules allow any size aperture, and permit front blades up to .10" wide.)

Another useful vision enhancement is a small aperture mounted close to the eye where it can significantly increase depth of field to allow a sharper view of both sights -



Unless you're using one of the open notches instead of the aperture, there's little reason to ascribe unsatisfactory grouping to the 1901 sights. The groups you've shown in this thread aren't bad, but do show some vertical stringing that may indicate vision challenges.

[keith.herrington]

Sorry to step on your toes, but...

They are crude and by almost any modern rifleman's definition of the term. The biggest issue is how far away the rear aperture is from the eye. This point is best demonstrated by virtue of what changes were made to both the 1903 when the sight was moved to the rear of the action and on the Lee Enfield where they did the same thing. When I want an example of a refined sight setup on a battle rifle I use the examples below:




Both of these rifles have very narrow front sights similar to the Krag and both are capable of better than MOA for the 1917 and 1.5 MOA for the LE.

Having said all of that I enjoy shooting the Krag every bit as much as the other two, maybe more. As for my vision, I agree entirely. Having the right glasses makes all the difference. I don't like or use a glasses mounted iris, but rely on the right prescription to help.

Final point - The quirkiness of the Krag's sights, much like the 1903's is one of its characteristics that make the gun both a challenge and a hoot to shoot. So don't take offense please, but it is what it is - a gun designed well over a hundred years ago, that even so can be made to shoot brilliantly.

[Parashooter]

Those who think the Buffington sights are crude probably take a broader definition* of the word. They are frustrating to adjust and the tiny, distant apertures plus narrow posts are unforgiving of poor light or imperfect vision - but the sight picture they provide (given strong light and good/corrected vision) is no less precise for the designed purpose of bullseye target shooting than an aperture of similar size mounted on a precision micrometer sight - and they're permitted in CMP matches (unlike those fancy micrometers).

*crude
adjective
1. in a natural or raw state; not yet processed or refined.
synonyms: unrefined, unpurified, unprocessed, untreated; unmilled, unpolished; coarse, raw, natural
2. constructed in a rudimentary or makeshift way.
synonyms: primitive, simple, basic, homespun, rudimentary, rough, rough and ready, rough-hewn, make-do, makeshift, improvised, unfinished, jury-rigged, jerry-built, slapdash.

[mhb]

Mr. Herrington:

Thank you for your response - though so long a time had passed since my initial post I didn't expect to hear from any user.
I'm glad you have had a positive experience with your CMP barrel, but uncertain which of my original observations you disagree with: you haven't slugged the bore of your barrel and didn't install it yourself, or provide any feedback on the issues I noted, from the gunsmith who did the work.
I do note that your targets appear to show evidence of bullet yaw, which is not ordinarily seen in properly stabilized bullets - but I can't say what effect on accuracy it does or may have: more shooting at longer ranges may provide more information on this topic.
FWIW, I prefer the 1901 sight to any of the other types found on Krags - while it is not to be compared to properly located (rearward) aperture types, it does provide useable adjustment (especially when a sight micrometer is available), and the windage is better than on the 1905 sight used on the 1903 rifles, since the adjustment is free of backlash and can be positively locked to prevent unwanted movement.

Good shooting:

mhb - Mike

[keith.herrington]

Some additional details

Thank you for your response - though so long a time had passed since my initial post I didn't expect to hear from any user.
I'm glad you have had a positive experience with your CMP barrel, but uncertain which of my original observations you disagree with: you haven't slugged the bore of your barrel and didn't install it yourself, or provide any feedback on the issues I noted, from the gunsmith who did the work.
I do note that your targets appear to show evidence of bullet yaw, which is not ordinarily seen in properly stabilized bullets - but I can't say what effect on accuracy it does or may have: more shooting at longer ranges may provide more information on this topic.
FWIW, I prefer the 1901 sight to any of the other types found on Krags - while it is not to be compared to properly located (rearward) aperture types, it does provide useable adjustment (especially when a sight micrometer is available), and the windage is better than on the 1905 sight used on the 1903 rifles, since the adjustment is free of backlash and can be positively locked to prevent unwanted movement.

Good shooting:

mhb - Mike

Mike,
I didn't answer your issues point by point because you described what I had to deal with as well. My gunsmith was quite pleased with the results from a mechanical perspective. The mounting screws for the rear sight are a non-issue. Any competent gunsmith can resolve this in his sleep. When the barrel was indexed and torqued to spec, the headspace was minimum plus .002". From my perspective that translates to slight resistance in closing the bolt on a new WW case. The diameter of the case at the neck after firing is .339" and a loaded cartridge with Sierra/Hornady bullets measures .335", or only .003" - .004" (a max of .002" on each side) clearance in the neck. As to the yaw, that is not at all uncommon at 100 yards when shooting long, heavy bullets. It commonly takes 200-300 yards for the bullet to "go to sleep" and become completely stable. That's why I prefer doing accuracy testing at 300 yards and not 100. I don't know what other issues you are looking to resolve, but from my perspective the Criterion barrel is well worth giving it a try.

Keith

[mhb]

Keith:

Mike,
I didn't answer your issues point by point because you described what I had to deal with as well. My gunsmith was quite pleased with the results from a mechanical perspective. The mounting screws for the rear sight are a non-issue. Any competent gunsmith can resolve this in his sleep. When the barrel was indexed and torqued to spec, the headspace was minimum plus .002". From my perspective that translates to slight resistance in closing the bolt on a new WW case. The diameter of the case at the neck after firing is .339" and a loaded cartridge with Sierra/Hornady bullets measures .335", or only .003" - .004" (a max of .002" on each side) clearance in the neck. As to the yaw, that is not at all uncommon at 100 yards when shooting long, heavy bullets. It commonly takes 200-300 yards for the bullet to "go to sleep" and become completely stable. That's why I prefer doing accuracy testing at 300 yards and not 100. I don't know what other issues you are looking to resolve, but from my perspective the Criterion barrel is well worth giving it a try.

Keith

Thanks for the further info. My main concern was with actual experience in resolving the issues I found objectionable, and the results in shooting, after installation. I object to the issues I listed because they are ones that the gunsmith should not have to deal with at all, in installing what was advertised as a fully finished, short-chambered replacement barrel (though in the white). And, as a barrel maker myself, I can't think of any good reason why the groove diameter should be so much larger than the nominal (and industry standard) .308", when made by a knowledgeable and experienced company, which Krieger surely is (and, presumably, the successors at Criterion).
As you did not say that your gunsmith had to ream the chamber to final dimension, I must assume he found it (as I did) to be fully chambered already - and to full Government spec. I am not surprised that the headspace was good - since the Krag barrel is seated against an internal shoulder in the receiver, it should be, so long as the receiver locking seat and the bolt lugs are also relatively un-worn and not deformed.
As to yaw, my experience is that it is seen in cases where the bullet is either over or under-stabilized - and that is certainly not the case with the heavier bullets and velocities for which the Krag was designed - loads such as you reported using. I have never seen evidence of yaw in the Krag with any weight of bullet from ca. 174 to 220 grains at the velocities obtained with loads in the correct pressure range, and that includes barrels with considerable wear and groove diameters from .309" to .311" - I do not shoot reduced loads, and, with the exception of using nominal .308" bullets in the .309" barrels, do not use undersized bullets.
Please let us know what results you get at longer ranges, when you have the opportunity.

mhb - Mike

[psteinmayer]

Just out of curiosity Keith, are you using standard or magnum primers with the 4350? The reason I'm asking is I started using magnum (CCI 250) primers with my 220 gr/40 grains of 4350 rounds. The magnum primer ensures a more complete burn of the slower 4350. It definitely improved my accuracy!

[keith.herrington]

I have not used CCI Magnum Large Rifle primers, but I will give them a try.
Keith

[gnoahhh]

I didn't notice the out of round bullet holes when first viewing these targets, but I see them now. I don't understand how a bullet that is yawing from the git-go will smooth out over a longer distance. If anything, it'll get worse, no?

[Dick Hosmer]

Ever watch photos of tracers - how they spiral ever tighter the further they go?

[keith.herrington]

Sometimes yes, often no. Long heavy bullets often start off with a slight wobble that dampens out over time, usually within 300 yards. Short light bullets do as well but much much less. The barrel on the Krag has a 1 in 10.5" twist, plenty fast for bullets in the 200 - 220 grain range. However, the muzzle velocity is rather low, about 70-80% of a 308 or 30'06 and even less for a 300 Win Mag or similar cartridge. Velocity translates to RPMs as the bullet spins its way to the target. If the RPMs are too low, wobble sets in. Based on what I see in the photos, the Hornady is yawing the most, the Nosler much less and the Sierra almost none at all. That matches what I saw at 200 yards when I first shot the gun. The Nosler and Sierra were the more accurate with the Hornady close behind. I plan on shooting the gun at 200 yards this coming weekend and see how the new loads perform.

However, I shot the gun today with the Hornady 220 RN loads today at 100 yards. As one contributor on another thread suggested I shot a load with 40 grains of IMR 4350. Here is the result at 100 yards.



However, I shot reduced loads all the way down to 36.0 grains. Most had poor results, but two loads, 37.0 and 37.5 grains of IMR 4350 showed promise:




When I get more Hornady 220 RN bullets I'll dig into these a little bit more.

By the way, the elevation change you see is due completely to velocity and powder charge. No sight changes were made for elevation but a slight windage change was made to center up the groups.

[psteinmayer]

Looks like you're getting there. Were these with the CCI 250s or 200s?

[keith.herrington]

CCI 200. I've got a bunch of prepped brass with that primer and need to use it up first. Next batch I'll try the CCI 250s.