Squib with VV 3N37 Powder

[bluetopper]

Today I had my first squib ever. It was in a 357 case and 7.0gr of Viht. 3N37 powder behind a 148gr double end wadcutter bullet.

I was shooting a Smith model 19, 2 1/2" barrel and the Tula primer pushed the powder and primer out to where the wadcutter bullet was just at the end of the barrel. The powder did not ignite at all and there was lots of powder left in the barrel so it was no fault of mine and my reloading.

Does 3N37 require a magnum primer? I did not think so till now.

 

[leefan]

Notice that we have a rash of squib threads?

 

[243winxb]

Range brass? Pick up with different brands & head stamps.

 

[bluetopper]

It was previously spent brass I reloaded myself. If you want to call it range brass, go ahead. What does that matter?

 

[56hawk]

7 grains sounds really low. Some slower burning powders will not ignite with reduced loads. I had this happen to me with H110 in a 500 S&W it jammed the bullet in the forcing cone and compressed the powder into what looked like a solid rocket motor in the cylinder.

I've shot thousands of rounds of 38 Super loaded with 3N37 without any problems, but those loads were a lot closer to max.

By the way, where did you get your load data? I looked on Vihtavuori's website, but they don't list that bullet:

http://www.lapua.com/en/products/reloading/vihtavuori-reloading-data/relodata/6/27

 

[Walkalong]

Light load with the powder forward in the case. Use a faster flake powder for a light to medium 148 Gr DEWC load.

3N37 is better suited to higher pressure and likes better case fill. It's a great powder, but not a good choice for this application.

 

[bluetopper]

Well, 7 grains of 3N37 sounds like a good bit to me as deep as a wadcutter bullet seats. All the others have ignited with a pretty stout recoil.

 

[Walkalong]

Powder forward then? In some applications with some powders it can make a big difference.

I love the Vihtavuori powders, but when it comes to position sensitivity, they are average at best.

This would be easy to test on the next range trip if you have more of the.

 

[bluetopper]

No, I hadn't found any data for Viht. powders and a DEWC bullet. I came up with this load from the seat of my pants and a fair amount of experience. Evidently it is not enough powder, but from the report and recoil of all the others that seemed to fire fine and with great accuracy I'd be afraid to go up to 7.5 grains in a K frame gun. I think I'll just change powders and spend all the rest of these I have loaded with caution.

 

[243winxb]

You could try a mag primer.

We tested loads at both maximum normal pressures and at the starting loads (some labs calculate start loads—we shot them). Standard primers caused no ignition issues at the max load but posted higher extreme variations in pressure and velocity in the lower pressure regimes of the start loads. In extreme cases, the start loads produced short delayed firings—probably in the range of 20 to 40 milliseconds but detectible to an experienced ballistician. Switching that propellant to a Magnum primer smoothed out the performance across the useful range of charge weights and completely eliminated the delays.

Read more: http://www.shootingtimes.com/2011/01/04/ammunition_st_mamotaip_200909/#ixzz2stD164qp

 

[kitsapshooter]

the charge seems a bit lite, but with that amount of unburned powder i would think a primer issue. I have read some reports of issues with tula primers recently.

 

[243winxb]

Too Much Primer?

It was a classic case of high gas volume but too little temperature. The primer’s extra gas unseated the bullet while still trying to light off the main charge, producing one peak.

Read more: http://www.shootingtimes.com/2011/01/04/ammunition_st_mamotaip_200909/#ixzz2stDtH599

I cant see a fully seated WC moving, from the primer firing, unless neck tension was low. Like Walkalong said, a faster powder is needed. I would work up a loading in 38 special brass with that bullet.

 

[bluetopper]

It very well may be a tad bit light but I thought 3N37 powder was more versatile and took to downloading a bit more than this also.

What's puzzling to me is.....there is 38 Spl data for 3N37 at 38 pressures but the others I loaded at 7.0gr in 357 cases were markedly stouter than 38's, which is what I wanted.

Might have been just a fluke, I don't know.

 

[gamestalker]

With powders like this you can get sporadic ignition if the powder gets pushed forward of the primer, too light of a charge, or not a hot enough primer flash. Just because it functioned well all other times, doesn't mean the perfect storm can't happen if it is taken to the edge of it's table, or in this case having developed the load as you stated, by the seat of your pants. Same thing can happen with H110 when it's not loaded properly, which is why charge reductions aren't recommended with certain powders. Everything can go fine, and then one sketchy or questionable element of the load will cause an ignition problem.

GS

 

[Mad Chemist]

I use a lot of 3n37 for my hot 9mm loads. You need good case fill to get good performance from this powder. For 3n37 the range from min to max for most calibers seems to be pretty low. For many of the max published loads the powder is slightly compressed. My max 115 and 124gr 9mm loads with this powder are slightly compressed although they do exceed the published max.


3N38 is even worse than 3n37 with respect to reduced charges. It blasted unburnt powder all over the place when loaded at the min charge for 147gr 9mm.
I had started my workup at the min looking for a reduced recoil "powder-puff" load. Neither 3n37 nor 3n38 are the right powders for this application.

 

[Walkalong]

Found this .38 Spl data from 8-11.

140 Gr XTP

7.1 Grs 3N37

WSP primer

98 Degrees 56% RH

4" Model 10

The average velocity for 6 shots each was 899 Powder Back, 751 Powder Forward, and, 771 Powder Level.

A loss of around 150+ FPS when the powder was not back against the primer. There is even more empty space in the .357 case.

CAUTION: USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

 

[Mad Chemist]

"No, I hadn't found any data for Viht. powders and a DEWC bullet. I came up with this load from the seat of my pants and a fair amount of experience. Evidently it is not enough powder, but from the report and recoil of all the others that seemed to fire fine and with great accuracy I'd be afraid to go up to 7.5 grains in a K frame gun. I think I'll just change powders and spend all the rest of these I have loaded with caution."

I just poured 7gr of 3n37 into a starline .357case. Casefill eyeballed at < 40%, way too little even for a fully seated WC.

My defensive 9mm loads for 115 and 124gr bullets are both just slightly North of 7gr of VV3n37 and I have not yet blown up my G19. (I worked these up carefully). I seriously doubt that 7.5 grains is going to damage a k-frame chambered in .357.

Another option would be to check bullet length and seat the DEWC bullet at the 1st lube groove instead of flush with case mouth. That should give similar case volume as a similar weight LSWC. Then you could work up from the lower end of the 145gr LSWC data. VV manual lists 8.3-9.0 for the Intercast 145gr LSWC.

Or you could just start over with a different powder.

 

[noylj]

Where the H did you get a 148gn wadcutter load for .357Mag and 3N37? Talk about the wrong powder for the job. Look to Trail Boss, AA2, 231/HP38, Solo 1000, Bullseye, Red Dot, etc.
Spherical powders are hard to ignite and need a certain level of pressure and heat to burn. I would have expected 3N37 to still burn, since it isn't THAT slow.
If you have enough experience for "seat of the pants" loading, you KNOW that you are using the wrong powder. However, if only one round, then maybe you got the powder contaminated--though I have no idea how one would do that, either.
Wadcutters are for 650-800fps loads.

 

[bluetopper]

"Wadcutters are for 650-800fps loads. "


Hard cast double end Wadcutters are for however hard you want to push them even at magnum pressures with 2400 or H110 powders. Makes quite a devastating round.

I might have dampened the powder with too much spray on case lube before assembling.

 

[Mad Chemist]

Hollow base WC are for low velocity target shooting.

Hard bevel base or double-ended are a different animal.

 

[Mad Chemist]

Bluetopper,

Let me know if you tweak that recipe and get it to work. At first I thought you were going for a light load. However, if you're after a hard hitting DEWC you might be able to make it work. Definitely going to need to up the charge though.

 

[kilibreaux]

Modern powders are supremely reliable.
Modern primers are supremely reliable.
Modern guns are supremely reliable.

So what can cause a hand loaded round to produce a squib?

The Tula primers might be the cause...poor QC over in mother Russia.

The powder is not likely the cause...the abundance of unfired powder tells you the primer failed to generate enough "brisance" to get the job done.

HOWEVER...a MAJOR cause of primer failure is the HUMAN HAND! When handling primers people can contaminate them with oils that degrade the priming compound.

If you are one of those people who have "moist" hands you are the most likely culprit if you handled the primers during reloading.

 

[Walkalong]

The powder and light charge is likely the culprit here. If you increased it it would do fine at some point, and yes, you can drive the DEWC hard if you want, but since you are looking for a lighter load, a different powder is going to be more suitable.

If the primer fired, it's doubtful that was the problem. Never say never, but the odds are agin' it.

 

[rfwobbly]

I was shooting a Smith model 19, 2 1/2" barrel and the Tula primer

Personally, the Tula primer is far more suspect than the Vit powder.

 

[Mad Chemist]

I have little faith in Tula QC. I have seen Tula ammo that had some pretty scary defects. I had to help an older guy at the range when a round jammed in his pistol chamber leaving the slide a few millimeters out of battery. Took quite a bit of force to rack open the slide. The ejected round looked like it had been seated incorrectly and the case was torn and deformed. I examined a few more rounds and found one that I could pull open with my fingers This was 9x19 ammo sold in a little circular plastic tub. The guy who was shooting it said he bought it at Wally World.

Regardless of my opinion of Tula craftsmanship, I think bluetopper's problem is more due to the charge of powder than anything else.