.410 Bore Archives - Page 4 of 10 - SmallBoreShotguns.com

Rolling Average

Having completed the pellet counts, although not the full analysis, for the three cartridges I tested earlier this evening, it is difficult to escape the conclusion that a rolled turnover (RTO) closure is exceedingly damaging to cartridge performance.

I have heard it said in the past that the kind of crimp – 8-point, 6-point or RTO – make very little difference to overall performance and, beyond making life easier for the cartridge companies and their loading machines, is most often used as a means of avoiding unsafe chamber pressures via the adjustment it allows to “resistance to opening” – i.e. the amount of force which must be applied to open the case and propel the shot column out of it, up the gun barrel.

Although I understand the well-established relationship between crimp type and chamber pressure, I have never been convinced that the type of crimp applied to a cartridge is simply an irrelevance when it comes to performance and, since beginning to test .410 cartridges on a regular basis, I am more sceptical than ever.

Once again, the ubiquity 12-gauge guns and their in-no-way-marginal performance probably obscures for most the knowledge of a significant factor affecting pattern quality.

Losing 5% of the pellets in a 12 gauge pattern is rarely significant. Even a 20% loss in some loads is neither here nor there. One will always have enough shot in the pattern to cover and break or kill one’s target. Again, however, we find that the .410 – although not principally different – highlights a feature of cartridge design which significantly damages cartridge consistency: the rolled turnover.

Non-Standard Deviation

Looking at today’s data and the data for the other cartridges we have previously tested, it is immediately clear that those cartridges with fold crimp are far more consistent than those with a rolled turnover, almost irrespective of the other components used to create them.

The only exception to this rule (to date) has been the Lyalvale 2″ cartridge which appears to show good consistency but, perhaps importantly, was largely tested at ranges of 20 yards only; perhaps more 30-yard patterns would begin to paint a different picture?

I would suggest again – since I think I have mentioned this theory previously – that the piece of card which closes the cartridge must be interfering with – and sometimes spreading – the shot in the column.

This interference likely occurs because the card acts as though a very small sail, slowing rapidly as it enters the atmosphere (from the gun barrel). In doing so, it is doubtless impacted by the shot, which, though it has much greater momentum, is not comparatively massive – especially where the RTO card is thick. These collisions – essentially random – deflect the shot and the card, leading to further interference until the shot has spread beyond the diameter of the card.

The result of all of this combined interference is essentially random. Sometimes a small number of pellets will be affected as the card flies quickly out of the cloud; at other times, the card will be buffeted along by the shot and take longer to fall to the ground, affecting / deflecting more pellets before it does.

I presume that this variance correlates with the number of pellets remaining in the useful pattern area and the larger range of variation seen with RTOs (as opposed to fold crimps) with the standard deviation in pellet counts for a particular pattern test.

In Short

It would appear that cartridges completed with a folded crimp will give best performance. Today’s cartridges, all having RTOs, gave very poor performance, even with the supposed advantage of larger shot and relatively low velocities. They were also noticeably inconsistent.

On the other hand, the #7 version of the Eley “Fourlong” cartridge (the #5 and #6 versions of the same cartridge were tested today) has a folded crimp and produced some of the best, most consistent performance the SmallBoreShotguns team has ever seen in a .410.

From inspection, the #7 loading appears to use a different powder, but is otherwise identical (wad, primer) to the #5 and #6 loadings. This is strong evidence as to the value of a good, firm, folded crimp over a rolled turnover.

Aside: Keeping the Pressure Off

Although several notable sources of reloading data indicate RTO (i.e. less resistant) crimps for some particularly thumpy reloads, I am not in favour of this approach, for the reasons described above.

I have always thought that if one fears excessive chamber pressure, it is likely an indication of trying to use the wrong powder for a given load. It would be far better to change the powder or quantity of powder and use a good, strong, 6-point fold crimp on the case, than add a card and an enormous degree of randomnimity to the loading’s performance.

I suppose the evidence is on my side: does anyone reading this know of a top-of-the-range clay cartridge made with an RTO? I can’t think of a single example.

To Be Expected

I’ve just returned home from a quick patterning trip during which I was able to shoot 12 patterns with the three new .410 cartridges.

Results appear to be as expected with perhaps a slight hint at the benefits of a reduced shot charge – the lighter Hull cartridge appears pattern as well as, if not better than the Eley #6 cartridge, although the rolled closures of the Eley cartridges probably contributed to what appears to be disappointing performance.

Numbers to follow later or tomorrow.

The End of An Eley

I wandered further afield yesterday, to a shop I’ve known existed for some time but hadn’t yet visited. Unfortunately, their range of .410 ammunition was very small, comprising only two brands: the 3″ Fiocchi #6 cartridge which the SmallBoreShotguns team have already tested, and the Eley 2½” “Fourlong” loading containing #5 shot.

Whilst my feeling is and always has been that #6 shot is too big to be employed in a .410 and that #5 borders on the ridiculous, we will nonetheless do our willingly-adopted duty and pattern test the new acquisition, along with the other two cartridges awaiting testing, on Tuesday evening next week, weather permitting.

I believe that, once that testing is complete, we will have covered the whole of Eley’s .410 range. We will then seek to find suppliers for the Lyalvale and Gamebore ranges, which remain largely untested.

Edit: In fact, we’ve since remembered that the supersonic version of the #6 “Extralong” and its #5 counterpart remain untested, so almost the end of an Eley. (How embarrassing – Ed.)

I’m also pleased to announce the arrival of a new – and hopefully interesting – article on the subject of The English Disease.

The contents of the Eley “Fourlong” 12½g / #5 cartridge.

At Last!

It is is some satisfaction that I am able to report that my new shotgun certificate arrived in the post today. Hunting will resume shortly – perhaps as soon as this weekend, time allowing.

New Cartridges

I’ve put the new certificate to good use already. Other than collecting my shotguns from the local RFD – who very generously waived fees in view of the short duration and my being a loyal customer – I also acquired four new boxes of cartridges. Two them, although unlikely to produce world-beating patterns, given the loadings of 11g/#6 and 12½g/#6 respectively, will be pattern tested in the SmallBoreShotguns .410 test gun in the next few weeks:

Two new, previously-untested loadings for pattern testing by the SmallBoreShotguns team: the Hull “Game & Clay” 11g/#6 loading on the left and the Eley “Fourlong” in 12½g/#6 flavour on the right.

I was also able to acquire the “other” box of cartridges for another of our forthcoming experiments. We intend to compare, as directly as we can, the effect upon patterns of a change in muzzle velocity of 500fps in the hope of demonstrating with evidence the value of what one might call “more moderate” velocities than English shotgunning seems to prefer.

On the left in the picture below is the subsonic Hull load I mentioned in a previous post and on the right is the loading most similar to it that I was able to acquire at my local shop, their top-of-the-range “Sovereign” brand.

Two boxes of Hull cartridges: a subsonic loading of 28g/#7½ on the left and a supersonic version of the same load on the right.

Admittedly, there are at least two important differences between the cartridges other than the muzzle velocity: firstly, the “fast” load has a fibre wad, not plastic and second, the shot contained within the cartridges is likely to be somewhat harder being a premium brand. Hull list 5% antimony for Sovereign, as opposed to 2% for most of their “budget” lines – we assume the subsonics fall into the latter category.

We’ll mention these factors again when we do the write-up. Of the two, I’d expect the hardness of the shot to make more of a difference, but neither to significantly affect the result. Nonetheless, we’ll try to account for these differences in analyzing the pattern data. Unfortunately, the shop had no plastic-wadded Sovereign cartridges in stock, so it was a question of buying what they had rather than what would have been ideal.

All of this came after requesting some of the plastic-cased Eley “Grand Prix” 30g/#6 and discovering that the shop hadn’t got a single box in stock to perform the “plastic versus paper” comparison I’d originally planned to do first. “I’m sorry – we only have the paper version,” was the reply. I found myself thinking that that seemed a rather pleasing response!

Snatched Opportunities

The final box of cartridges was the Hull 23g/#7 “High Pheasant” load for 28 gauge. I’m not really sure why I bought these, except that I remember using some in the past and – looking back on it – unfairly writing them off, when – like most things in shooting – the problem was undoubtedly operator error.

I like to keep a box of cartridges in the glove box of my car in case I’m ever in the position of needing to grab a gun and snatch an opportunity for a wander around the hedgerows under time-limited circumstances. This is quite often the way I end up going hunting, given that there are small people living in the house.

Since I’ve found that the fit of my 28 gauge is vastly improved with the addition of the leather stock extension I’ve borrowed from my friend, I’ll just have to remember to take that gun on these occasions and give the Hull cartridges a proper field test before I revert back to my long-term favorites, the Eleys. I’m sure they won’t disappoint.

I’ll curtail this here as there are a couple of Baikals locked in the cabinet that need also need trying for size with the stock extension attached. I suspect the results with those will be just as good as with the 28 gauge. I’ll let you know the outcome next time.

Resolution

I received a somewhat unexpected telephone call at around 5pm this evening.

The firearms enquiry officer dealing with my SGC renewal called this evening, in haste, to conduct the via telephone, the interview he’d clearly intended to do earlier but, due to “system and staff changes” hadn’t so far managed. This blindsided me somewhat, as – being a lazy Sunday evening – I’d just finished a pint of rather strong cider – safely, I thought – and although in the process of turning my thoughts to dinner, hadn’t managed to eat anything before being put on the spot!

I felt rather tipsy, if the truth be told, but I believe I answered all of the questions to his satisfaction and was told that my certificate would be issued tomorrow. Whether it will be hand delivered or simply posted, I don’t know, but it won’t be long before I’m back out, testing, patterning, hunting.

The whole situation has been – undeniably – an inconvenience, but everyone I have thus far spoken to from the constabulary’s firearms team has been both apologetic and apparently embarrassed at what appears to have either been excessive workload or an oversight (or both). Given that they themselves have admitted I put my application in with plenty of time to spare, I can’t give them a shining review, but I will say this: dealing with a customer’s problems in a pro-active and helpful way goes a long way to repairing any ill feeling caused by the initial mistake and I actually feel I’ve received good service from them, even if everything didn’t quite go to plan.

Game Supper

I’m cooking venison burgers for my wife and her friend tomorrow. It was going to be pigeon burgers, but my wife was concerned that feeding her “fitness guru” friend birds containing lead shot might not fly (the lead, rather than the pigeon being the problem).

For that reason, I suggested that we might eat some of the muntjac I dispatched with the .410 before Christmas – the theory being that bouncing it off a car (I didn’t do that bit, if you recall) and head-shooting it (that was me) was less likely to have introduced lead pellets to the parts I have just ground to be turned into burgers tomorrow.

With all that going on, I couldn’t miss the opportunity for a little taste test. I put one of the tenderloins aside before I started, then rubbed it with plenty of salt and pepper and fried it when I finished. It was delicious. It almost makes me want to take up deer stalking again. Almost.