Hi everyone,
I am working up different loads for my 700 classic in 223. It has a 9 1/4 twist, and shoots 60 & 55 gr V-max pretty well. I thought I would try the 68 gr hornady, as this twist is supposed to handle up to 69 grain bullets.
What I got were 6" groups at 100 yards and oblong tears with all 4 loads I tried.

Here is my question- would greater muzzle velocity possibly stabilize these bullets? With 3 of my loads, I am below published max by at least .4 grains, and there are no pressure signs. It seems logical to me that greater velocity means faster rotational speed, which is stability. However, logic has failed me before.

Thanks for any input.

Doug

I have a Rem 700 PSS with a 4-14X 40mm scope. The chamber has been reworked to Ackley Improved. Rifling is 1:9" and your rifling should be the same.

This gun is getting 1/2" groups at 100 yds without too much effort. You gun should be able to match this. The bore needs to be cleaned about every ten shots. Seriously cleaned. You shouldn't be getting any "keyholing" of your bullets. I wonder if your target backing is causing bullets to tumble.

A six inch group might be OK with iron sights, but it's not OK for a good scope that is properly mounted. I'm able to shoot eggs at 300 meters with this rifle/scope combination -- 40 gr. VMax. Granted, I have the loads worked out and am pretty fussy about load specs.

You've got a glitch somewhere.

Scoped rifle?
Clean bore?
Steady bench rest?
Consistently loaded ammo?

More discussion of these points would be helpful.

Hi Genghis,
The rifle has a 4-16 scope and gets .5-.7 groups with the 55 and 60 grain Vmax loads it likes.
I find it kind of fussy- some loads it loves, some it really hates. Vmax's shoot well in the good loads, but will open up to 3 inches in loads it does not like. It does not like Hornady psp (55gr) or Winchester psp (55gr) and some FMJ bullets (62) I tried.
I built a simple bench on top of a workmate that seems to work well, and the target is a commercial 5-bull backed by cardboard. I haven't gotten aropund to buying a real rest, so I use bags of shot. Today the best group was .46 with Varget and the 60gr Vmax, and that was after I shot the 68s. The 68s are definitely flying sideways.

I am really a shotgunner and just getting into the rifles, so I appreciate all the help.

Thanks,
Doug

ps- do you ever see copper fouling with the naked eye in your bore? I do not clean it during a target session, so it often sees 30-50 rounds through it between cleanings and I have never seen any.

The faster a bullet goes thru a barrel the faster it spins. It seems like the oblong holes are tipping bullets.

How fast are they going with the four loads? The site www.bergerbullets.com shows a 1-10 required for a 70 gr bullet.

[ 06-03-2002, 08:24: Message edited by: Don Martin29 ]

It's possible to over stabilize a bullet. When this happens the bullet gets pointed up in the air as it rises on the trajectory and it still points up as it comes down the other side of the trajectory. But that shouldn't matter in 100 yds with a flat shooter like .223 Rem. Still, you might be having this happen.

You gotta clean that bore!!!

Get the right stuff for cleaning:

One piece rod. Bore guide. Proper brushes, jags, patches. I spend more time cleaning at the range than I do shooting. Spare no expense for cleaning supplies!

After about ten rds you get really fouled and begin to wear out the bore. Solvent and a brush. (Get a bore guide!) About a dozen passes with the brush/solvent and then go set targets. Give the bore ten minutes to let solvent dissolve the coppering.

Then a proper jag with a proper patch. Two of these with solvent and then two or three dry ones. The first solvent patch is going to be hard to push in the bore and it's going to come out black and nasty -- with a fair amount of crud ahead of it.

Small caliber and high speed fouls the bore fast! With 30 cal guns I shoot maybe 50 rds without cleaning, but with a 22 cal I clean every ten rds.

You have an expensive gun. Take care of the bore!

My gun has a love/hate relationship with bullets. Hornady VMax 40 gr. shoot nice and tight. 55 gr Win. FMJ (cheapo $5/100) are worthless -- 6" groups/100 yds.

50 lbs of sand at Home Depot is about $3.00. You can toss a towel over the heavy plastic bag.

My sand bags are made from the legs of worn out bluejeans. Fill a heavy plastic bag. Tape it shut and sew it into the leg of the jeans.

I found a cafeteria table at GoodWill. Put the legs on a heavy plank. I bought a cheapo Hoppe's bench rest for $50. Should have doubled the money and got something decent. But I've modified this a fair amount and it works for me.

ISP won't let me link. Cut/paste these for photos of my gear.

http://pages.chatropolis.com/general/geo/benchscape.jpg

http://pages.chatropolis.com/general/geo/bench1.jpg

[ 06-04-2002, 11:57: Message edited by: Genghis ]

Twist Rate Basics:

As velocity increases, the twist rate necessary to stabilize the bullet decreases.

As the length of the bullet increases, the twist rate necessary to stabilize the bullet increases.

Bullets do not spin faster over the same distance as velocity increases. The bullet leaves the barrel at the same 1 rotation per 10 inches no matter what its velocity (rotation over distance traveled). However, the rotational speed over time does increase - revolutions per minute.

Twist calculator - http://www.realguns.com/calc/riflingtwist?results

The real guns twist calculator is based on the Greenhill formula, which is quite, shall we say, "rough". It's only marginally useful on 224 cal bullets.

Check the JBM version, it's about as good as it gets on the net. By changing velocity, you may be able to do enough of a "what if" to answer your question.

http://www.lascruces.com/~jbm/ballistics/drag/drag.html

Also, have you checked your ACTUAL twist? Not what it is supposed to be, but what it *really* is? Sometimes twists are off. HTH, Dutch.

I've had trouble with the Hornady 68 grain match bullets too, I believe it may have been related to the cannelure as the rifle shot fine with the 69 grain Sierra. I'd try some Sierra 69's as a test.

I agree with Dave,

The 1-9 twist barrel you have should work just fine with 69gr bullets. If the Hornady's are giving bad results, try a different bullet (Sierra 69, Berger 70, etc.) and play with the seating depths.

Also: Re 15, Varget, 760, and 4895 all seem to be favorites of High Power shooters using 69gr bullets at the 300yrd line.

Thanks guys!

Back to ther loading bench.

Doug Koenig