How much does cold effect velocity?

[Richc2048]

I have a new to me tanfoglio limited and tried to make a major load using titegroup. I went with a few books minimum and worked my way up.

The powder website states 4.2gr @ 908fps and 4.7 at the 970fps "roughly" out of a 4" barrel.

I made all the way up to 4.5 gr thinking they'd be fine but that gave me an average of 910fps. The 4.2gr were in the 860fps area.

These loads were shot in the cold. Like 30 degrees and almost snowing. My oal was 1.135. Can the cold effect it that much or is it like I hear about every gun is different? I thought for sure 4.4 would get me there.

Any experience with how much slower 30 degree weather can do to titegroup?

[AJE]

The powder matters more than anything else.

WST gets hotter as it gets colder. I tested this because my chrono results at a match were lower than they should have been (still made power factor they were just lower than I had tested).

I switched to Bullseye since it was only a few FPS difference between my ambient temperature mags and the one I left in the freezer for a few hours prior to testing.

[drewbeck]

Titegroup isn't known to be super temp sensitive. I also don't think I have ever had a book load ever make "book FPS" for me. There is a certain amount of conservancy built into loading books generally.

Everything we vary to any degree from a book will change the outcome in FPS. Unless you are shooting the exact load, same brass, primer, powder lot, bullet, neck tension, crimp, temperature, altitude, out of that exact barrel you will not end up with the same result.

If you increase the OAL any amount you will lose FPS from the book. Your barrel could be slightly slower than theirs, etc, etc, etc.

Basically the book just provides a good starting point and ballpark of what to expect. Your results seem in line with the range and they are consistently just a little slower. I would look for pressure signs and if nothing is there, I would continue to slowly creep up until I hit major.

Generally speaking most of us are way beyond the books but use the experience of the group to double check it's within normal load ranges from others experiences. I would search here and I think it will make you more comfortable with crossing the book max. If you really want to sleep easier just ask an open shooter how much they are over a max book load it will blow your mind.

The books are written for the masses and to saami specs. Once your outside Saami specs you are "above max" and off the grid, always proceed with caution and awareness but use others experience to help guide you.

OAL is a huge deal and will dramatically change how the powder acts when it burns. Powders with big pressure spikes are also something to be very aware of. I don't have a good titegroup 40 load to give you any kind of comparison, but I do have some unicorn dust for you if you want, we can chat next time I see you

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[jayjay1]

I highly agree with everything drewbeck has said.

Temperature influences velocity different.

Some powders are almost temperature neutral.

Others get faster when it is hot or cold, and vice versa.

With the pistol powder I love most, the Lovex D032 (similar to Acc. No. 2), I loose velocity in summer.

So I do some testing before I go to the matches in summer under hot weather conditions.

That being said, I prefer heavier bullets and don´t want to overload such a fast powder.

Seating your bullet further out (growing your OAL) will minimize pressure and you can put some more powder in.

So you should check out, if longer OALs will fit your chamber.

But we are talking about 0,1 or 0,2gr. more, what might be possible this way.

And just for the books, a longer barrel would help too.

(Yes, I know...)

P.S.:

If you are willing to handle different loads for summer and winter, be always sure to use the right one in the right conditions.

Edited February 7, 2015 by jayjay1

[zzt]

Newer research shows that WST is "fastest" at mid-range temps. It is slower at freezing and at 80 deg.

Many powders are very temp sensitive, and some not so much. VV N310 for instance, is one that is very temp sensitive. My softer bullseye load goes 749fps @ 85 deg., 733fps @ 56 and 705fps @ 41. I have fired it at freezing temps, but not chrono'd it. It barely operates the action, and the brass barely dribbles out.

[Richc2048]

I was surprised to see the near max load barely made their min velocity. I even have a longer barrel but did load it .010 longer. I just had no idea how much the cold effects it. I'll have to recreate those loads again and try it when it's fair weather, like above 60 degrees.

It must be temp sensitive because I see people reaching major PF in the 4.3-4.4 range easily when loaded at 1.135.

[Hi-Power Jack]

It must be temp sensitive because I see people reaching major PF in the 4.3-4.4 range

Aside from temperature, each gun is different.

Some barrels are "slow" - require more powder to achieve 168 PF.

[SilverBolt]

Titegroup to make major? That is a very fast powder to be pushing that hard. Be on the lookout for pressure spikes as your loads increase.

[Richc2048]

Thanks Silver. I'll keep an eye out. It seemed that on paper titegroup would make it easily but I may take an offer of different powders from drew if it's the same on a warm day.

[Postal Bob]

Barrels, and the cold will affect the velocity.
You didn't state what bullet weight you're using. But assuming 180gr, it usually takes 4.6-4.8 gr titegroup out of a 5" barrel to make major pf(916 fps).

Edited February 7, 2015 by Postal Bob

[Richc2048]

Barrels, and the cold will affect the velocity.

You didn't state what bullet weight you're using. But assuming 180gr, it usually takes 4.6-4.8 gr titegroup out of a 5" barrel to make mafia pf(916 fps).

Yup. 180gr played extremes. That makes me feel better knowing it takes that much. I'll have to try the 4.6 I created and see how that goes. I almost made it with 4.5 and 30 degree weather.

[USPSA72536]

I'm shooting titegroup 4.8/4.9 out a 5" barrel and make major!!

[d_striker]

I was surprised to see the near max load barely made their min velocity. I even have a longer barrel but did load it .010 longer. I just had no idea how much the cold effects it. I'll have to recreate those loads again and try it when it's fair weather, like above 60 degrees.

It must be temp sensitive because I see people reaching major PF in the 4.3-4.4 range easily when loaded at 1.135.

I just checked my chrono data spreadsheet. Looks like 4.2gr Titegroup w/ a 180gr plated at 1.125" made 166.7PF out of a 5.25" XDm.

20 shots, some below 165PF, some above.

[Richc2048]

I'm shooting titegroup 4.8/4.9 out a 5" barrel and make major!!

What gun are you shooting out of? Are you loading long as well?

[USPSA72536]

Out of a 5" barrel on a M&P 40 Pro. And No

[IntenseImage]

180 Frontiers w 4.7 TG @ 1.13 made a 170ish PF from my 5" M&P

[Richc2048]

I chronographed today and found out the temperature didn't effect the speed much. I was hoping for about 40fps but 10 shot strings confirmed they stayed about the same. The spread was a little less but the average increased only the slightest. And so slight that it may have just been different cases that changed the speed. I think I'll have to bump it up to 4.7 or even 4.8 with titegroup.

Cfe pistol made major PF easily with just slightly over their min charge. I did notice a thump with it but it may have been the fact that it was over 180pf. I'm kinda liking the cfe pistol so far. But I don't really feel differences in powder much so I'm just basing this on the fact that I can make major very easily. I don't like that I'm pushing titegroup to max or slightly over published to reach it.