Long jumping little bullets.

[Tesoro]

Ive have a box of 100 gr Hornady amax I bought for my 6.5CM. I thought it might be novel to try a little bullet so I started by checking the CBTO measurement. I then put a bullet in the neck so that the bearing surface gets a normal full neck grab. The bullet has a .13 jump in that configuration which is excessive for any decent accuracy expectation. The COAL was 2.62 so plenty of room in my mag.

And then I looked at the Hornady manual for their COAL with that bullet and it was 2.71. I usually never look their published COALS but did in this case. So I set up a bullet in my comparator at their 2.71 and I had barely half the neck grabbing the bullet. The jump is now .066 which is still on the high side but more doable I guess

So what to do?? I read about some guys shooting the 95g and 100g in the creed without any mention of jump and throat length. So are they inadvertently doing it with a massive jump and proper neck grab or are they pushing their bullets way out on the neck and compensating for this with more tension?

IMO these bullets dont really fit the cartridge and chamber. Thats obvious. I am happy with my 120-123 grainers which where designed to fit so wondering if its just a waste of time to play with anything smaller than that. Or is it acceptable to seat that long? I have always followed the old school rule of bullet dia to neck grab length so it just looks odd and delicate to me to have a bullet half hanging out of the neck and especially for feeding with my mag.

 

[Bart B.]

As long as the case neck grips bullets correct for its use and performance objectives, neck grip length matters not.

Size necks smaller for more grip.

 

[Comrade Terry]

How did they shoot?

 

[Tesoro]

I didnt load any as I dont have a tighter bushing than one that does .002 and didnt feel like neck turning to reduce my runout by a tho. I still dont like the excessive jump due to the bullet form plus I dont see any ballistic advantage downrange for a 95/100g over a 123g. So I am leaning towards the thought that they are a waste of time for this cartridge and if I want to shoot small bullets fast then I'll get a 6mm creed!

 

[Comrade Terry]

So I am leaning towards the thought that they are a waste of time for this cartridge....

Very well could be a waste of time, Tesoro.

But you'll never know for sure unless you let your target give you the answer.

 

[Tesoro]

Very well could be a waste of time, Tesoro.

But you'll never know for sure unless you let your target give you the answer.

Well I am going to give it a try to have a novelty load. I got some feedback on the creed forum and guys have had sub moa luck with the .66 jump and 2 tho tension. if nothing else the recoil will be pleasant.

 

[dellet]

How deep you “need” to seat them depends on what you are shooting them from.

It will depend on how well they feed since there is more leverage on the bullet with less to hold it. I've seated plenty of 30 caliber bullets at .120" deep.

Without a magazine or in a single shot you can soft seat them and allow the bolt to finish seating then with a jam with just enough bullet in the neck to hold them straight.

The other thing is that the Amax in general seems to be very jump tolerant, so you may not need to worry so much.

 

[jds holler]

Well I am going to give it a try to have a novelty load. I got some feedback on the creed forum and guys have had sub moa luck with the .66 jump and 2 tho tension. if nothing else the recoil will be pleasant.

Hey Chris, you'll never know until you try. One time I was loading some of the stubby little 35 gr V-Max's in my 218 Bee, and for kicks stuck a couple groups worth in some 222 shells that I had all prepped and ready. I can't remember the numbers, but the jump was pretty horrible. Took them out and grouped in the .3's with them. Go figure. jd

 

[ClassCat]

I have had barrels that like +10 on seating depth.Another of my GO TO seating depths when all else fails is 40 off. I have had several barrels that loved that.
Let the Rifle tell you what it wants.

 

[Dusty Stevens]

Just because some other forum says they use a light bullet they may not even have a clue how far theyre jumping they just throw it in there. To be optimal youd need a different chamber with less freebore. That being said if jumping that far takes you from a gun thatll do 1/2” to a gun thatll shoot 9/16 most would not even know its not optimal and it would get lost in the noise

 

[billlarson]

to jump......... you must have straight loaded rounds......
bill

 

[Barlow]

I have a couple of 6.5x55 Swede's, a 94 and a 96. They are loooong throated. An 85 gr Sierra will not be in the case when I checked distance to the lands. I seat them at 2.290 cbto. Make sure they are in far enough to be straight. I used this load the other day to foul the barrel on my 96 for some other test loads. Barrel cold and clean with a smidge of oil in it. Three shots at 100 were .880 and the last two at .246. My old 94 shoots them just as well. Runout .003 or less. You never know till you pull the trigger. Barlow

 

[243winxb]

Light, shorter for caliber bullets. - Like a 55 gr in 243 Win.*

The front of the bullet needs to seal the bore, before the base (full diameter shank) of the bullet exits the case mouth.

Better alignment and less hot gas blowing past the bullet? Longer barrel life?

More bullet, neck contact may help the powder burn better. So a short OAL should work with a long jump.*

Just how i see it. No proof.
Edit added*

 

[Tesoro]

Well I'll try a handful just to learn something but I am not going to load them hanging on by the lips of the case mouth and stuff them in my mag!
I did order today some 107 smk for an alternative light bullet tryout. They have a great bc and are about as long as a 123g amax. At least the nose will be way down the tube if the ogive is a bit further back. I looked at all the small bullets and the 107 seems to be the most attractive of the bunch with a G1 of .46

 

[Tesoro]

Just because some other forum says they use a light bullet they may not even have a clue how far theyre jumping they just throw it in there. To be optimal youd need a different chamber with less freebore. That being said if jumping that far takes you from a gun thatll do 1/2” to a gun thatll shoot 9/16 most would not even know its not optimal and it would get lost in the noise

Agree on all counts! And I noticed on the 'other forum' that the posters who said they shot small groups with those little bullets in the 6.5 all spoke about referencing the load book coal in comparison to what their coal was. Their measurements were 2.xx so they were actually measuring coal and not cbto. Thus they didnt know what their jumps really were as they didnt know what the jump was for the load book published coal. oh well...I always wondered who uses those published coals and now I know!

 

[Mikemci]

I have a Rem. 6mm that shoots sub 1/2 moa with a 100gr. Nosler Partition. My jump is .071"

 

[Tesoro]

Well I loaded up a test batch of 100g amax. I decided to go long and they are only seated about 1/3 of the way into the neck. I used the smallest bushing expecting 2 tho tension but I only got 1 tho. I said what the heck and then checked my bullets. They were all .2625 to .263 dia. Hornady I guess...Oh well. I made them straight so they all have max 1 tho runout. They have 56 jump.
Will hit the range before too long and see what happens to the paper.