357 sig / 147 gr xtp bullets?

[Brandon9250]

Im having an issue with these 147 grain xtp bullets it seems that my cases are squating after i seat my bullet. My crimp seems ok but a little weak the bullet will set back a little after i chamber the round but not bad. Im assuming im not going to be able to use these bullets the 125 grain works great any answers will help thanks!

 

[vaalpens]

Can you post a picture to show what a squatting case looks like.

My experience with 357sig is that most of the time you will see some setback when chambering/cycling the rounds. If it is minimal then you should be good to go.

I normally cycle dummy bullets at least 4 times and then perform a bathroom scale test. If it passes both tests then I am happy with it.

I have not loaded the 147gr XTP yet in 357sig, so I don't know how difficult it is to load in 357sig.

Realguns.com shows a load for Hornady 147gr HPBT-XTP with a COL of 1.140". So I assume they should be loadable in 357sig.

 

[Brandon9250]

I will post some pics tonight when i get home, its hard to see but when i chamber the round its to tight and will not go in the whole way and it seems its only after i seat my bullet it does that.

Im almost thinking the ogive may be below the case mouth i also loaded some dummy rounds last night it would be tight the first 2 cycles. Then it will seat in my chamber but the bullet would be in my case, this is with no powder of course but usually i use a compressed load so setback isnt a problem

 

[vaalpens]

You also need to do a plunk test using your barrel after you made the round.

Drop it in the barrel and it should make a plunk or plink sound. You should then be able to rotate the round while in the barrel. It should rotate freely. Then you should turn the barrel upside down and the round should just fall out without any help.

What COL are you using for your load?

 

[Brandon9250]

1.134 is what i measured from most factory rounds, so thats my aiming o.a.l +/- .002. And my 147 grain rounds wont feed into the chamber shortly after the neck where i seem to be getting that buldge.

im using rcbs dies and an expander die im not sure why im getting a bulge after i seat the bullet its got me drawing a blank... All my measurements are good after sizing and it passed the plunk test untill i seat the bullet. On 125 gr i dont have this issue

 

[Sunray]

"...getting a bulge..." Seater die is down too far. Same thing happens with bottle necked rifle cases. Raise it up and adjust the seater plug.

 

[Brandon9250]

Ive done that, the seating die is about .600 away from my shell holder. Ive tried setting it up higher and lower with no difference, its almost like the bullet is doing the bulging.

 

[vaalpens]

Are you crimping and seating in one step?

What is the diameter of the 147gr HAP bullet?

Are your sure you have flared the case mouth enough to accept the bullet?

You also need to check your COL. I don't have a 147gr XTP bullet, but it seems a 1.134" COL could be short. All the HAP/XTP load data I have seen are always at least a COL of 1.140"

 

[Brandon9250]

crimp / seat is 2 steps different dies i am flaring case pretty good but bullet still seems a little tight but not excessive. (No bullet shavings)

bullet diam. Is .355 and the 1.140 is maximum c.o.l

Maybe my issue lies in the flare not being big enough?

 

[Rule3]

Hornady data lists a COL of 1.140 with their 147 gr xtp bullet.

Tested in a Sig 229 of course

 

[vaalpens]

There is nothing wrong if it goes in tight since you need good neck tension in any case. If there are no shavings and the bullet will sit in the mouth before seating, then I would not flare more. Too much flaring is not a good thing, especially with 357sig.

There must be something else going on. A posted image will probably help identifying the issue.

The 1.140" COL is the standard. I load at different COL's depending on the bullet and what my gun will accept. One of my loads is loaded with 1.150" COL without any issues. I load with COL's of 1.120", 1.125", 1.135", 1.140", 1.150".

 

[Brandon9250]

When i made my c.o.l i used a lightly crimped round and gently closed my action and measured it is where i came up with the 1.134 my sierra guide claims 1.140 is max but i know what you mean my 7mm mag is over the books recomended oal

 

[gamestalker]

One of the greatest misconceptions about rimless cartridges, such rimless types that head space off the case mouth, do not attain neck tension by increasing the crimp. The .357 sig which of course is a bit of a hybrid that falls some where in between, in that some sources state that it head spaces off the mouth, while others report it does so off the shoulder, but one thing is clear, it still doesn't utilize a roll crimp like a rimmed cartridge does.

So, that considered, increasing the crimp to manage set back is not recommended, nor will it resolve neck tension issues. The more taper crimp one applies, the less neck tension that is achieved. And when it becomes really excessive, the shoulder will buckle. thus increasing loss of neck tension. Neck tension is achieved through the resizing process.

Over belling of the case mouth will also cause neck tension issues, and especially so with a cartridge that has a super short neck, such as the sig. The mouth should only be belled just enough to facilitate seating bullets without shaving. More than that will create a situation that can't be resolved without running the brass back through the resizing die. Thin or worn out brass will also cause neck tension issues.

If memory serves me correctly, the 147 gr. XTP is a boat tail. So if that is so, then all one really needs to do to seat bullets, is to chamfer the inside of the case mouth, then seat without any belling at all, thus no crimping is necessary either.

GS

 

[Brandon9250]

Thanks game perhaps i am applying to much crimp and to much belling... I will look at my setup and maybe adjust i tried to chamfer the mouth and i still shave some bullet going in but not to bad i will get back to you tonight

 

[Rule3]

Yes, the 147 bullet is a BT.

I do not load for it but as GS states, you should need very little if any flair.

Also I do no know if case length will matter but it is a necked down cartridge so perhaps trim to length may help.?? (believe me,I am not a pistol brass trimmer!

but the neck may grow on this cartridge

 

[JimKirk]

As stated above ... the 147 gr. XTP does have a small boat tail and needs zero flare to load ....chamfer .... it really needs only the slightest of crimps .... Hornady list a COl of 1.140" and it works good at that length ....

800X will also shove that bullet right along ... if you can get it to meter right...

 

[Brandon9250]

Loaded a dummy round, oal 1.150 no flare, small chamfer, backed crimp off so it barely engages, backed seat die off further, set back test was 60# then my scale shut off lol i think i got it thanks for your help gs, jim, rule,vaalpens,sunray, & rule 3 im gunna go load me some bunker busters!

 

[Brandon9250]

Also ill be using unique powder only because its all i got for now & its a compressed load even tho my setback test was 60+ pounds

 

[vaalpens]

Don't forget to cycle the dummy round(s) through your gun a few times and measure the setback. Also perform the plunk test.

What made you decide to go with a 1.150" COL instead of the 1.140" COL?

Another test I do is to take a sized case and place it over the dummy round bullet. If there is some bullet showing between the case mouths then you are good to go. If the case are touching and you can rotate the sized case with no resistance, then the start of the ogive is at the case mouth or below it.

Here is an example showing plenty bullet between the cases.

 

[Brandon9250]

I actually went back to my 1.134 i tested brass & nickel cases my nickel need to be shorter, it appears they are a lil tigher (like slide closes i just need to give it a little smack)i may just switch to brass i really only went to nickel for looks haha you guys advice helped out! Im kinda new to pistol reloading but any 7mm mag questions im your guy lol

 

[vaalpens]

I don't trim my 357sig bras, but I do sort them by length. So when I load a bullet where the ogive will be very close to the mouth of the the case, then I just use my shorter cases for the load. I'm not sure if it makes that much difference, but it does give me some peace of mind.

 

[Rodentman]

Vaalpens, Thank you for the tip using a sized case to check the ogive issue. I use those 147g BT bullets. I don't flare the case mouth and I don't crimp. Works great at a hair over 1.14 in my Sig 229. I have used 125 bullets, put a cannelure in them, and crimped into that. Very time consuming and I no longer do that. I use a Dillon sizing die.

 

[vaalpens]

Vaalpens, Thank you for the tip using a sized case to check the ogive issue. I use those 147g BT bullets. I don't flare the case mouth and I don't crimp. Works great at a hair over 1.14 in my Sig 229. I have used 125 bullets, put a cannelure in them, and crimped into that. Very time consuming and I no longer do that. I use a Dillon sizing die.

My pleasure. It is not my original idea. I got the idea from realguns.com where he showed this method as a cheaper alternative than using a specified tool. It is close enough for me to get some idea.

I have used 125 bullets, put a cannelure in them, and crimped into that.

Oh oh, her we go. Are you saying the 357sig headspaces on the shoulder and not the case mouth?:banghead:

It seems the 1.14" or just a bit over works good for the HAP/XTP design, and I think most load data shows the 1.14" also.

 

[Rodentman]

When I was using the cannelure method I frankly wasn't sure about the headspacing as I had read several different views, and still do.

I am very comfortable with the 147g bullets and in fact load them in 38super using no flare and no crimp. They work fine as does the .357 sig. I use my Cabela's points to keep a steady supply of those bullets.

 

[JimKirk]

I can tell you for a fact that the 357 SIG WILL headspace on the shoulder ... it may not suppose to ... but it WILL ... if you size it to do so...

If you don't believe it ... take a 40 S&W case and size it to fit your chamber .... load a (<)mid to lite load(357 SIG) and it will shoot all day long ... that 40 S&W case will be way short ... but it will headspace just fine ... Would I load those 40 S&W cases as regular or heavy loaded 357 SIG ... AIN"T NO WAY... !!!