key hole with custom tube.

[big-johnson]

hey guys if your bullets a-r hitten da target sideways it sounds like u got more problems than 55 grain bullets believe u need 2 jack it up an run a new pipe undernieth it

 

[4xforfun]

hey guys if your bullets a-r hitten da target sideways it sounds like u got more problems than 55 grain bullets believe u need 2 jack it up an run a new pipe undernieth it

Got it. ???

 

[bouddha]

My Ruger 77 Heavy Varmint in .220 Swift shot 55 Nosler BTs, SPs and a few others, up to some 60 grs., no problems.

 

[AlNyhus]

Tod, your calculations on JBM are incorrect. With a .810 bullet in a 14 twist barrel @ 3500, the Sg is well under 1.0. A shorter bullet will solve your issues.

A good bullet for your combo is one made on the .705 jackets like the Berger 52's, etc.

Hope this helps. -Al

 

[AlNyhus]

Yikes ! ...makes one wonder how Mike Ratigan won the FISS (Super Shoot) shooting a similar bullet at a similar velocity, at the same twist..... that according to JBM .....is poorly stabilized?

Those bullets are on the .705 jackets...fully .080-.095 shorter after pointing up than the .810 long BTips. -Al

 

[4xforfun]

Tod, your calculations on JBM are incorrect. With a .810 bullet in a 14 twist barrel @ 3500, the Sg is well under 1.0. A shorter bullet will solve your issues.

A good bullet for your combo is one made on the .705 jackets like the Berger 52's, etc.

Hope this helps. -Al

Al,

In my later posts I pointed out that my original calculations were wrong and posted the correct numbers . With the JBM and all the correct data.....3900 FPS, 10 Deg F. .71 bullet length, 52 gr ect..... I get 1.017 factor.... Ragged edge. Any colder or slower and I will be screwed. Need to go shorter/lighter.

 

[LHSmith]

Yikes ! ...makes one wonder how Mike Ratigan won the FISS (Super Shoot) shooting a similar bullet at a similar velocity, at the same twist..... that according to JBM .....is poorly stabilized?

Those bullets are on the .705 jackets...fully .080-.095 shorter after pointing up than the .810 long BTips. -Al

Actually, at this point in the conversation, the OP was referencing Berger 52 FB

 

[xswanted]

how many of you out there have sucsessfully shot 55 grain bullets out of your 22-25-/220 swift/22whateveryoucallit?

I am kinda curious.

Thanks,
Tod

I shot 55gr Bergers out of a Ruger 77 with great success, my dad also used them as the go to bullet.

Using 4064

 

[AlNyhus]

Actually, at this point in the conversation, the OP was referencing Berger 52 FB

He had referenced having the Berger 55gr. Match bullet on hand, which is .750 long. The Berger 52's are .719-.720 long.

Either way, a shorter bullet will get things settled down.

Good shootin'. -Al

 

[Kingfisher]

My 22-250 1:14 shot for crap with everything except 2 bullets and 1 powder. Go figure. It would stabilize everything up to 55 grains fine, but they just weren't accurate. I was finally able to get a decent group with Reloader 10x and 52 grain Shilen Microjackets. When I couldn't get the Shilen bullets anymore the 52 gr. Matchkings shot nearly as well. It would also shoot plain jane Remington 55 gr. PSP's right at 1". The Shilen and Mk's would average 1/2 that. The point is, my rig was very picky... unfortunately. The whole thing is currently with Mark Pharr undergoing a rebarrel to 6XC.

 

[4xforfun]

Actually, at this point in the conversation, the OP was referencing Berger 52 FB

He had referenced having the Berger 55gr. Match bullet on hand, which is .750 long. The Berger 52's are .719-.720 long.

Either way, a shorter bullet will get things settled down.

Good shootin'. -Al

Al, re-read that post..I said that the only bullet I had on hand LESS than 55 gr is the 52 gr berger.

 

[AlNyhus]

Ooops..my bad, Tod. Glad you have it figured out, though.

Good shootin'. -Al

 

[LHSmith]

This JBM is interesting. I was under the impression that nipping off the plastic tip on ballistic tips had no ill effects....which I have done for years on hunting cartridges so they fit in the magazine while keeping the ogive close to the rifling. Now I see if the stability factor calculates on the marginal side, this factor could cause problems......although it has not shown itself on target so far.
It would be interesting in this case for the OP to cut off the tips on the 55 gr BT's and try them, as my data input into the formula takes it into favorable stability numbers.

 

[Rustystud]

I would shoot nothing heavier thann 53 grainers with a 1:14 barrel.
Nat Lambeth

 

[NateHaler]

hey guys if your bullets a-r hitten da target sideways it sounds like u got more problems than 55 grain bullets believe u need 2 jack it up an run a new pipe undernieth it

Your first post is noteworthy. :

 

[NateHaler]

My brother has an old Rem 700 that he had re-barreled to a 22-250 30 degree improved 1-14 twist Hart BBL. This job was done 15-20 years ago by someone I will no longer let near my guns.

Anyway, he has fired 300 or so FF loads, some factory, some reloads...probably never on paper. he decided to start working with it, so I gave it a thorough cleaning. he started with varget and molyed 55 gr Ballistic tips. Pure disaster.....groups ranged from 2 -4 inches.

Start with 40 gr. bullets! ;D

 

[AlNyhus]

Be aware that there are two ways to compute Sg on the JBM site:

-The Bullet Drag and Twist. This was developed by Dr. Robert McCoy and is based off his McDrag and McGyro work. This is the accepted gold standard used by professional ballisticians.
http://www.jbmballistics.com/cgi-bin/jbmdrag-5.1.cgi

- Stability. While simpler, it greatly overestimates the twist required for stability.
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

The Stability chart is the chart that's linked on Berger's website. Further investigation will yield some surprising facts, for those interested in understanding this important aspect of rifle accuracy.

Good shootin'. -Al

 

[4xforfun]

Al,

I checked out the first link to the JBM site....holy krap...about the only info they asked for that I even understood was bullet weight, caliber, and twist rate!!!! Everything else went strait over my head!!

 

[LHSmith]

I am caught up in this stability business. I ran the numbers on typical 30 BR BR bullets and they come up in the red....I ran a typical 6 ppc match bullet and it comes up yellow. For all practical purposes, these bullets shoot hundreds of sub 0.250 aggs every match season @ 100 and 200 yd events.
The OP has a problem that "seems" to be related to stability ( although sideway holes in a cardboard box @ 25 yds. and "angled" holes at 100 yds. has me wondering if you can 100% make that claim......the target must be square to the shooter to come to that conclusion.....and taking a read on anything but good target paper is a guess), but at the very least he has a load that shoots below his standards.
I would not place a lot of confidence in running numbers through a program that obviously only has useful info for shooting well beyond the range for which this rifle was built for......(i.e. 14 twist).......its a 400 yd rifle at best.
Of course, each rifle tends to like different loads...as the posters have confirmed....and this may be just the case....some barrels do not like plastic tipped bullets. It would be useful info if the OP did cut the plastic nose off some bullets and run them with the same load. I do hope the OP uses some type of wind flags for his testing...and I find .224 bullets like a good jump....0.03" to 0.09"

 

[BoydAllen]

Get a hold of some 40 grain plastic tipped bullets. Don't worry about the jump, drive them hard with a suitable powder, and let us know what you get. All of this theory is no substitute for testing.