sp01 chamber length

[wcmesa]

Has anyone tried cutting the throat deeper on the barrel so that you can use a bullet with a ogive further forward on the bullet? If you have were there any ill effects? I am loading a nei 147 gr at 1.120 oal but would rather load a little longer.

[ChrisStock]

I am loading my SP01 with 147GR Berry's,Winchester, and Kead Bullets with Alliant Promo/Red Dot and also Ramshot Zip to 1.15 without issue. I haven't tried a longer OAL because 1.) 1.15 works 2.)I didn't see it recommended to load longer anywhere in my load data books.

Out of curiosity, why would you want to load them longer? Just curious. As far as your original question, I don't want to change anything that I can't change back on my pistol. Angus Hobdell set it it up, and I am loathe to do something that can't be undone.

(Edited because I submit instead of enter)

Edited December 24, 2007 by Lighteye67

[JayC]

I haven't had an issue with OAL and the barrel, but where you run into problems is the magazine. Some bullet designs (esp. in 147g) will hang up on the cut out for the mag release. I've been able to load some 124's to 1.160" OAL and feed fine. I'm still using 124g bullets, but with the brand now, I have to load to 1.150".

I have found that in most of my guns, I get better accuracy by loading longer.

[Stefano]

At the beginning of this (just closed) shooting season I've owned for a while a SP-01, jus to make some tests (note: my favourite match-partner is a Tanfoglio Stock II ….).

After a serious trial-period of several thousands of bullets fired with it, I’ve understood that CZ doesn't like heavy load like 155 or 145 grs, and – on the contrary – never had any problems with the same gun using 124 and 115 grs. Bullets.

The real issue is (IMHO) the bullet profile, and in particular 147/155 grs bullet’s profile.

The second problem: CZ doesn't like round nose.

CZ is very sensitive with bullet profile, because the free bore in the barel is very short. So the bullet is touching the rifling when you use a heavy weight or a round profile bullet.

If you want to continue to use heavy weight bullet you need to increase the free bore inside the barel to avoid trouble.

But ... is it worth ??

My advice: shoot 124 grs. bullets !

Edited December 24, 2007 by Stefano

[Shay1911]

I second the bullet profile advice. For example, when I was using master blaster 147's, a long truncated cone profile, I could load them to 1.15. Now that I use Precision, a 147 cone with raised shoulder, I have to load them to 1.082! In order not to hit the rifling.

These are the Precisions: http://www.precisionbullets.com/IMG/9-147fp.jpeg

Shoulder hits rifling unless you load below 1.09.

I also have some 124's with the raised shoulder and have to load them to 1.082 as well, so it has more to do with the bullet profile than bullet weight.

Hope this helps.

[Franksremote]

I had the same experience loading the Berrys bullets, 1.01 or so with their 124gr HP bullets. MGBs in 124gr JHP load out to 1.14-1.15 without issue. Didn't think to ream the chamber as the loads worked fine at either length, the pucker factor was just a little too high at 1.01 though and went with the 124gr MGB JHPs. Before reaming, I'd make sure the loads will fit in the mag. YMMV

[Radical Precision Designs]

I suppose that if you went to your friendly, accomodating pistolsmith, he could re-ream your chamber for a standard fit. Personally I like to use the Manson 9mm Nowlin chambering reamer. I have been shooting Major 9 for a while using 115 JHP, 121 IFP and 124 JHP from Montana Gold which are known for having a short ogive and a long base. I have loaded my cartridges as long as 1.180 without any marks (shaving) from the barrel's lands. I prefer to load them usually no longer than 1.170" to avoid their sticking on my spacer installed STI magazines.

I haven't seen any "ill effects" of having my barrel reamed that way, (Which is actually considered a normal chambering!!!) nor do I see any possible problems if it was done on a CZ. IMHO.

[Shay1911]

Hey Venry, the short chamber in the CZ may be one of the reasons it is so accurate. You just have to pick the right bullet profile that wont get stuck in the rifling.

Shay

[Radical Precision Designs]

Hey Venry, the short chamber in the CZ may be one of the reasons it is so accurate. You just have to pick the right bullet profile that wont get stuck in the rifling.

Shay

Shay-

Gee, whiz ... I dunno !

I have no problems shooting the same cartridges I described in my 9mm CZ Champion, which is a "factory" built open gun. And, I didn't ream up that barrel !!

But, maybe you are right with those Precision plasticoats in 147 grs. I never tried one of those in my CZ Champion, since I'd rather shoots lighter bullets in it. Hey, Shay, maybe I'll bring the CZ Champion to "Markham" one of these Thursday nights and try some of your loads ??

[Shay1911]

Anytime

[wcmesa]

The bullet im useing is a truncated cone with a slight round nose to it. im sizing them on a lyman lube sizer to .356 but i have a star on the way so i may wait until it comes in before i do anything. I do have a gunsmith around here that has reamed a kkm and lone wolf barrel for me so that i can load long. The bullets loaded to 1.160 fit in the mag with a little to spare. The cast bullet is only a little longer than a 147 hornady xtp, if i take the recomended oal of the xtp and add the extra lenght of my cast bullet it should be loaded to 1.125 according to the manuel. But i ussually like to load as long as the chamber will allow. Im gonna wait until i get the star lube sizer just in case it is a inconsistancy in the lyman. If i do get the "free bore" cut i will post the results. Thanks all to the replies and views you have given me.

[TrueDoubleTaper]

You can keep the chamber the exact same length, just simply have it throated a bit deaper for the bullets you want to use. The only possible negative is that when you go back to shorter AOL's or different bullets, accuracy may be lost slightly due the the increase length before your bullet contacts the lands... I do not think you would ever notice the accuracy decrease.

[ebg3]

I have the same question/problem with my EAA Stock using MG 124 jhp's. I have to load to 1.075" to not hit the lands. And my mags could handle rounds loaded to 1.24"! I can load to 1.17" or so with fmj roundnose bullets...don't know about cast bullets. I think I'll have it throated a bit. It shouldn't hurt accuracy.?

[JayC]

Strange, haven't used the Precision's. Been using Delta Precision's 124g RN and can load to 1.160", have also been using Frontier's 124g RN and load to 1.150". When I was shooting Zero's 147g JHP, is when I found the mag problems with the bullets hanging up and not feeding, therefore had to load them to a shorter OAL. I've checked both brands of RN loads and neither contact the lands of the barrel. I've also never had either of the RN loads hang up in the magazine. Good to learn something else to put into the knowledge bank.

[killarbb]

i know that when i tried the 124 gr laser cast in my sp 01 i ran into the same thing. the profile of th ebullet caused it to require short OALs. really short. ........almost scary short.

bb