Cold Clean--Warm Fouled

[ronlaughlin]

This morning i planned to go fishing, but it was -3. Also, i was curious to see if the old diesel, loaded with all my shooting paraphernalia, would start. He was just fitted with a whole new set of glow plugs. Well, i moved the rifle, powder, and a clean target from the shop to the truck. The original plan was to go fishing, so the truck wasn't plugged in. Happily, he started right up, and after the windshield defrosted, we headed for the hills.

The load was 110g Blackhorn, 300g Deep Curl, crush rib sabot, CCI 250 primer. The rifle was the Dream Season. The range was 200 yard. The temperature through the shooting, was right at zero. In the beginning, the air was moving which i could feel, and it also moved my breath different directions. However, the moving air wasn't really a breeze, just gentle moving air. The first two shots were some high. The first was from a cold clean barrel. The second shot was from a barrel with one shot through it. The loading pressure using the crush rib sabot wasn't much, but seemed it was "enough".

However, when i loaded the third shot, i felt very very little resistance whilst shoving the bullet 'home'. The large change is loading resistance was very noticeable, and actually kinda surprising. This third shot went a way lower than the first two. The fourth shot loaded very easy, just like the third. The fifth shot loaded the same as the third, and the fourth. These easy loading shots made me wonder if i shouldn't be using a more tighter sabot, but they sure all hit in the same area, albeit, a lot lower than the first two shots.

What i wonder/wondered is if the bore expanded because it warmed, or if the Blackhorn residue acted as a 'lubricant', or both. At any rate the 'loose' load sure made for a different point of impact, and the force to put the bullet on the powder didn't seem it was enough.

Then a swirly breeze came, and i knew there was no use to shoot any more, but i did shoot twice more. The smoke from the sixth shot blew straight left, and that is where the bullet hit--a way left. The smoke from the seventh shot blew to the right.

Then i went home; then i went fishing. It warmed up real nice--36 degrees. All i caught was 2 itty bitty perch, about the size of a goldfish.

 

[ENCORE50A]

Pretty much the same results with many shooters, including myself. Blessed are those who's rifles shoot to the same POI clean or dirty.

 

[SteveH]

Don't know if I will ever shoot out to 200', but still interesting results. With my X7, I've pretty much stopped cleaning it during season or at least if I know I'm going out again soon.

Ice fishing? You have a heated shack I hope.

 

[ENCORE50A]

Ice fishing? You have a heated shack I hope.

Good question! My question would be, is it tied down or in the same spot?
35mph winds here with -25° wind chill. That's why I'm inside 8)

This is why I'm staying inside this evening: Temp dropping to -22° with wind chill to -35° I wonder if a rifle would even fire that cold......

 

[ronlaughlin]

Can't say my rifles would fire at -22, but my Omega has fired at -18. Even the Accura with a modified breech plug has fired at -13. The Omega breech plug just works with any standard shotgun primer, as does the Accura. The coldest temperature the Omega ever was subjected to overnight in the cab of the truck was -18 not very long ago. Interestingly, the primer used that morning was a Federal 215.

 

[ronlaughlin]

............ Ice fishing? You have a heated shack I hope.

A tree fell on the shack, and that was the end of it. These days i wear modern warm clothing, and sit on a padded chair outside. Mostly it isn't too bad, unless the fish aren't biting. The other day i caught the largest perch ever--11", and watched eagles beg for small fish, and deer grazing, and visited with nice people, and was fishing, and was alive, and so..feeling some cold, beat sitting at home.

 

[jims]

My muzzleloader would not fire at -35 degrees with me sitting behind it. That would just be cold for me to be out trying.

 

[BuckDoeHunter]

BH209 acts like a lubricant for me. When it's cold outside and I'm loading on a clean bore, I have to load my rifles indoors when I use Barnes TMZ bullets, otherwise, it's a real bear to load the tight fitting sabots after the barrel cools. After the rifle is fired once, loading is much easier.

I have noticed that popping a few primers on a clean bore also acts as a lubricant. Once, after popping 3 primers in the bore of our TC Impact, i swabbed the primer residue to distribute it throughout the bore (I'm experimenting with first shot POI using different techniques) and then loaded a 250gr TMZ, it was much harder to load compared to not swabbing the primer residue.

 

[ENCORE50A]

Bullet and sabot seating forces in my Pro Hunter.
Using Barnes 250gr. TMZ bullets and BH209 propellant
CLEAN COLD BORE…… swabbed with 2 clean patches, 2 primers fired
32# constant loading force to push bullet/sabot down the barrel
106# bullet seating force

AFTER two fouling shots………..
• 52# 104#
• 48# 100#
• 58# 108#
• 48# 110#
• 54# 106#
Average force to load sabot……….. 52#
Average bullet seating force………..106#

 

[sabotloader]

Ron

One other thing you might think about... As someone has already mentioned the 'ambient air temp' and the effects on the sabot.

I will just mention what I have found with no scientific facts.

For myself and in my case most of my hunting is in the cold temps that you refer to. The polymer formulation used in Harvester sabots gets very hard and looses some of its pliability. I have always felt that because of this the sabot does not really mold itself to the lands and grooves of the barrel. This same theory helps me explain why Harvesters appear to work better in the warm temperatures or in a warm barrel, when the Harvester is able to mold itself to the bore.

On the other hand I have found that the polymer formulation use be MMP works very well in really cold temperatures and because it maintains pliability it does mold itself to the bore.

One of the reason that I believe this other than experiences is loading a snug harvester or a snug MMP in sub zero weather. Often the Harvester will be shaved slightly as it goes through the crown and the MMP NORMALLY does not. And I would suggest the MMP is easier to load all the way down the bore than is the Harvester.

On the warm end of the spectrum the MMP gets very gummy in warm weather or in a hot barrel. Gummy is probably not the right word in that it does not stick to the bore - it just becomes very soft in the presence of abnormal heat.

Just sharing..
__________________

 

[ENCORE50A]

Ron

One other thing you might think about... As someone has already mentioned the 'ambient air temp' and the effects on the sabot.

I will just mention what I have found with no scientific facts.
For myself and in my case most of my hunting is in the cold temps that you refer to. The polymer formulation used in Harvester sabots gets very hard and looses some of its pliability. I have always felt that because of this the sabot does not really mold itself to the lands and grooves of the barrel. This same theory helps me explain why Harvesters appear to work better in the warm temperatures or in a warm barrel, when the Harvester is able to mold itself to the bore.
On the other hand I have found that the polymer formulation use be MMP works very well in really cold temperatures and because it maintains pliability it does mold itself to the bore.
One of the reason that I believe this other than experiences is loading a snug harvester or a snug MMP in sub zero weather. Often the Harvester will be shaved slightly as it goes through the crown and the MMP NORMALLY does not. And I would suggest the MMP is easier to load all the way down the bore than is the Harvester.
On the warm end of the spectrum the MMP gets very gummy in warm weather or in a hot barrel. Gummy is probably not the right word in that it does not stick to the bore - it just becomes very soft in the presence of abnormal heat.

Just sharing..
__________________

Gummy.......... replace it with pliable

Normally I'm using MMP and other than testing the Harvester Crushed Ribs with Barnes, I have no other sabot force testing information.

Here's the deal on plastics/polymers. YES temps can and do affect them. I've worked with engineers at GM and plastics/polymers and heat or warm temps make a difference in how pliable it can be. Some have a very high difference in pliability difference when cold or warm. Heat, or warmth, makes them all more pliable to some extent AND so will moisture/humidity levels.
An example (fact), the simple push pins in your GM vehicle, say holding in a fender liner or such, MUST be able to be inserted with NO MORE than 10# force. Yet this push pin MUST retain. In the early years this presented a problem to the engineers. Plastics/polymer manufacturers recommend that it remain hydrated..... to a point. Its well known in the engineering community that both will dry, not necessarily becoming brittle but, will become harder.
Over 30 years ago, I recommended they use heat lamps in the plants to warm the plastics/polymers for easier installation. This process is used in many manufacturing processes today.

Unknown to me, that's probably why I keep my speedloaders in my pocket.....

 

[ronlaughlin]

Short Black Harvester Sabot

This morning it was -3 at the house. The old boy must have wanted to go for a ride; he started once again, without having been plugged in.

The Dream Season, powder, bullets, sabot, and primers spent the night in the much warmer shop. They were loaded up, and we headed out to 4700'. It was snowing like the dickens up there, and it was -8, but we were there, so we set out the target, and loaded the rifle.

Oops, it couldn't shoot. After cleaning it the last time, i put the wrong breech plug in the rifle. Couldn't shoot it. So..with the powder and bullet in place the breech plug was removed, and replaced with the plug that would shoot the large rifle primers. Some powder came out with the original plug, and some powder could be felt in the threads, and between the nose of the plug, and the barrel. The plug was tightened as tight as i could using a 1/4" ratchet, and some powder grains were smushed.. Well, i knew the first shot from the cold clean barrel was compromised, but what could i do but proceed. The shots are identified in the order they were taken. No wait time was taken between shots.

Snow doesn't seem to affect the bullets much. The snow was so heavy whilst taking shots 1, 2, and 3, i could barely see them holes through the spotting scope. Then the snow let up, and the target was more easy to see. However, the tape wanted to obscure the holes made by 4, and 5, because it was curling away from the cardboard. When the trigger was pulled for shot 6, a nasty gust of wind happened right then, and the smoke blew quite strongly left, and away.

Group 2,3,4,5,7, 8 measures 3 1/4".

Group 3,4,5,7,8 measures 2 3/8".

Group 4, 5, 7, 8 measures 1 1/4".


It does seem the use of the tighter sabot did tend to keep the first shots closer to the later shots. However, the load for the first shot was different than the load for the rest, and this means more, and more shooting is required, so for to see where the very first shot from a cold clean barrel will impact.

 

[ENCORE50A]

Great reading and info.