Well folks,
They,ve packed a bunch of 120 MKZ,s to try out. Should be interesting.
Hope everybody,s doing ok.

TS

Slimjim,
Can I get the load data you used for the 120 MKZ/22" Barrell/3200 fps/ for my 270 Winchester? Cavityback/copper. I,m using H4831 plus s cut.
Would this load be plenty for Black Bear critters ? Or do you suggest from your thoughts that I should stick with my Nosler Partitions in 150gr and 140gr bullets. I want to have a reliable load so while in the woods I would feel more than confident all mid range big game could be handled ok?
I sent a E-mail to Cavity Back on a question I had and to my surprise, the guy that first designed these copper Bullets in his garage called me back on his cell phone.Super nice guy to talk too. The first orders to manf. this design sold out very quickly. the 2nd. order sold the same way as the word started to get out by gossip. So, he said, this order was a much larger request to handle all the new and more order,s he gets. I wished him the very best for success with this bullet he designed and told him I and other reloaders would spread the word about them. Later, T.S.

Slimjim,
I have this gentlemen,s cell phone number that he gave to me .

Cavity Back Bullets. The developer. But I need input on rather I should post his number ? You guys let me know on what you think on this.

T.S. 02/26/2017 2:52 PM EST

TwoSeventy wrote:

Slimjim, Can I get the load data you used for the 120 MKZ/22" Barrell/3200 fps/ for my 270 Winchester? Cavityback/copper. I,m using H4831 plus s cut.

TS, I reloaded with IMR4350.

57.5 grains of IMR4350, Rem brass, CCI200, 3.215" COAL

You can look up the 120 Barnes on-line and use that as a guide.

www.hodgdonreloading.com/data/rifle

It looks like you will run out of case capacity before you hit max pressure with 4831. Load the MKZ as far out as you can without touching the lands.

TwoSeventy wrote:

Would this load be plenty for Black Bear critters ? Or do you suggest from your thoughts that I should stick with my Nosler Partitions in 150gr and 140gr bullets. I want to have a reliable load so while in the woods I would feel more than confident all mid range big game could be handled ok?

This is your call. If you develop a load with the 120 MKZ that you are happy with the accuracy and have confidence in, then considering using the MKZ. Otherwise, go with your old standby. How close will you be shooting?

ok, tks. probably no further than 150yds.

Slimjim,
On the load you just gave me for the 120 MKZ. If there is a crimp groove on this bullet, did you add a crimp to it ? TS

TwoSeventy wrote:

Slimjim, On the load you just gave me for the 120 MKZ. If there is a crimp groove on this bullet, did you add a crimp to it ? TS

TS, there is no crimp groove (cannelure) on the MKZ. I loaded the bullet so the base, gas check ring (middle ridge in groove), and 0.025" of the shank forward of the grooves. Though not required, I do use a light crimp on all my bullets, even monolithic. I have found it make neck tension more consistent. But I only use a collet crimp die (from Lee). Do not use any crimp feature integrated into the bullet seating die - they only cause more problems than they solve.

Slimjim,
Thanks for all your input of info.. I do have the complete Lee die set, so I can do this light crimping. On other kinds of reloading where they suggest there is no need to crimp, based on this quote that if you do add a crimp, will this effect cup pressure and did you consider this as not a problem to be concerned about ??

TKS. TS

TS, I have done pull tests to measure neck tension on the .270 Win. Crimping did not increase neck tension but reduced the variation in neck tension by 50%.

Slimjim,,
I will start light crimping with my Lee die on all my reloads. That was the only concern I had was on what crimping effect,s on cup pressure. It also should improve accuracy on your target.
Does the the half bullet press turning 180 deg,s help accuracy also ? Seem,s you mentioned this from my memory.
TKS>, TS

TwoSeventy wrote:

Does the the half bullet press turning 180 deg,s help accuracy also?

I learned this from Elvis. I have not done quantitative testing on accuracy improvement but it does improve concentricity measurably - which should help improve accuracy and reduce the number of fliers.

SlimJim,
I just found this Forum website discussing the MKZ cavity Back Bullet. FYI:

TS 68forums.com/forums/sh...tive-range

twoseventy....Id bet bushys left testicle that is Slimjims post/testing.lmfao

Elvis wrote:

twoseventy....Id bet bushys left testicle that is Slimjims post/testing.lmfao

Yep, I reckon you are right Elvis...those results look very familiar mate.