Reloading for old milsurp rifle, accuracy opinion sought

[Enfielder]

I've been trying different .303 British loads, and the best I can do is 3" x 2" groupings at 100 yards (with scope on 9X) on bench with sandbag. Photos below. Did not tweak scope, maintained constant point of aim. No wind, 65° F at time of shooting. Rifle hot from 10 warm up shots in 5 minutes. I'm not an expert marksman & accept partial blame, even on a benchrest (I can see the crosshairs moving a bit while I squeeze).

Is this pretty much the limit of accuracy for a bolt-action milsurp with frosty bore but very pronounced rifling ? I'm looking for WWII bolt-action milsurp shooters' opinions. Store-bought ammo gives me similar performance.

Loads tried:
20 shots fired with 37.0 gr H335 pushing a 174 gr Sierra HPBT.
10 shots fired with 38.8 gr IMR-4895 pushing a 150 gr Sierra SP (labeled B)
10 shots fired with 42.3 gr IMR-4895 pushing a 150 gr Sierra SP (labeled 2) Trying near min & near max for IMR-4985 in this target.
C.O.A.L. to recommendations in reloading manual, checked w/caliper
Neck-sized only...1st time reloaded for this brass collection.

[RaisedByWolves]

Heres something that might interest you.





http://www.theboxotruth.com/docs/edu79.htm

.

[cosmo05]

Try using 180 gr. Speer soft point with a flat base. I use 39.5 grs. Varget and they print 1" to 2" groups with iron sights out my LEs. Flat base bullets will perform better out of Enfields.

[GUNGUY45]

Heres something that might interest you.





http://www.theboxotruth.com/docs/edu79.htm

.

I'd slug the bore, and do some measuring before I'd ever think about using bullets of a larger diameter. That said it's an interesting concept.

[RaisedByWolves]

I guess it all depends on your level or reloading proficiency/knowledge. I have talked with this guy at length on another site and hes very knowledgeable and is quite the old timer of reloading.

Conclusions:
1. We carefully checked for pressure signs and found none at all. cases extracted and ejected easily and the primers showed nice, rounded edges, with no flattening.

Some may see this as throwing caution to the wind, others will probably recognize it as a valid method for checking your theory. If his barrel is as bad as he states, I see no reason for concern as it has surely gone out of spec.


.

[Enfielder]

Raised by Wolves: Excellent. I love Box-o-truth; great site.
Fortunately for me its even easier to try a larger bullet- Hornady makes a .312 diameter 303 caliber bullet (Hornady #3120). Perhaps I will try some. Hornady also makes a .3105 diameter 303 caliber bullet; I already tried these and they shot terribly (6 inch group) I even have what's left of the box in the classifieds for sale; they might work for someone else

I slugged the barrel with the fishing sinkers/grease/wood dowels method. Got excellent groove and land pattern on the lead sinkers. Too bad the Enfield has a 5 groove barrel. Yep, 5 lands, 5 grooves. Because of the odd number, can't use the micrometer or tips of the calipers to measure diameter I even brought them into work to share with the machinist/gunsmith and we confirmed the shadowgraph/comparator is of no use either with an odd number of lands/grooves. Still, with this odd number, I used the micrometer and guesstimate somewhere between .3110 and .3125. Definitely not a tight barrel as the .3105 bullets demonstrated.

With a minimum load, what is the risk of catastrophe shooting a .312 bullet out of barrel which might slug at .3110. ??? Explosion ? I have tried everything to clean it including electrode & ammonia, JB Bore paste right after shooting, Sweets copper solvent (great stuff BTW) The lands clean up bright, but the grooves remain dark, no doubt chemically etched by the corrosive ammo used in WWII. The crown is in good shape. As they say the barrel is "dark but with strong rifling"

I've read brief posts by customers having success with .312 bullets out of old Enfields, Arisakas, and even Mosin Nagants. I could tie a 10 foot string to the trigger. Opinions please.

[Flash]

Raised by Wolves: Excellent. I love Box-o-truth; great site.

I slugged the barrel with the fishing sinkers/grease/wood dowels method. Got excellent groove and land pattern on the lead sinkers. Too bad the Enfield has a 5 groove barrel. Yep, 5 lands, 5 grooves. Because of the odd number, can't use the micrometer or tips of the calipers to measure diameter I even brought them into work to share with the machinist/gunsmith and we confirmed the shadowgraph/comparator is of no use either with an odd number of lands/grooves. .

It is possible to get very, very close on an optical comparator, but not easy and maybe not truly precise, depending on your slug and your comparator. . But, now try this, if your "machinist" has access to "v-block" mics, flute-mics, spline mics, of the kind used for measuring fluted rounds - they come in 60-degree for 6-flutes, and appropriately angled for other, odd-and-even numbered splines. They are expensive, and they are not common. If those aren't available, PM me and I'll show you how to do it with other eqpt.

Flash

[Enfielder]

I'll ask about the tooling tomorrow. Before I repost the question as a new thread,

What is the risk of shooting a .312 bullet (Hornady #3120) out of bore that I've shot plenty of .3115 bullets (Sierra #2315) out of ? Would the extra .0005 nominal be a big explosion risk ? What the guy in Box-O-Truth did- Jumping from .308 to .311- seems a bit risky to me; I do not have enough experience to know better.

(sample measurements of ten of the Sierra #2315 bullets, .311 nominal diameter, .3116, .3114, .3116, .3116, .3115, .3116, .3115, .3115, .3116, .3115) rather fat .311's eh? [Starrett No. 230 micrometer...Mitutoyo .500 gauge block meaured .5000, Mitutoyo .250 gauge block measured .2499]

[Flash]

I'll ask about the tooling tomorrow. Before I repost the question as a new thread,

What is the risk of shooting a .312 bullet (Hornady #3120) out of bore that I've shot plenty of .3115 bullets (Sierra #2315) out of ?

You would not notice anything with just a half a thousandth difference. Nothing that you could measure , anyway.

Would the extra .0005 nominal be a big explosion risk ? What the guy in Box-O-Truth did- Jumping from .308 to .311- seems a bit risky to me; I do not have enough experience to know better.

The guys in B-O-T failed to do one thing - accurately slug the bore before the shooting commences, so that they would procuce meaningful (read "accurately measured") results.

They were making ENTERTAINMENT, not verifiable, repeatable, concise information. Yes, the entertainment is often worth it, in itself, but the resultant conclusions are hardly objective or quantifiable.

Flash

[notenoughguns]

That fellow was using a 1917 enfield in 30-06 and if I'm not mistaking ,(and I may be wrong) had a groove dia. of .311 to .312 same as the 303 brit. ( left over barrels from the 1914 enfield )